uLong ZEXPORT adler32(
    uLong adler,
    const Bytef *buf,
    uInt len)
{
    unsigned long sum2;
    unsigned n;

    /* split Adler-32 into component sums */
    sum2 = (adler >> 16) & 0xffff;
    adler &= 0xffff;

    /* in case user likes doing a byte at a time, keep it fast */
    if (len == 1) {
        adler += buf[0];
        if (adler >= BASE)
            adler -= BASE;
        sum2 += adler;
        if (sum2 >= BASE)
            sum2 -= BASE;
        return adler | (sum2 << 16);
    }

    /* initial Adler-32 value (deferred check for len == 1 speed) */
    if (buf == Z_NULL)
        return 1L;

    /* in case short lengths are provided, keep it somewhat fast */
    if (len < 16) {
        while (len--) {
            adler += *buf++;
            sum2 += adler;
        }
        if (adler >= BASE)
            adler -= BASE;
        MOD4(sum2);             /* only added so many BASE's */
        return adler | (sum2 << 16);
    }

    /* do length NMAX blocks -- requires just one modulo operation */
    while (len >= NMAX) {
        len -= NMAX;
        n = NMAX / 16;          /* NMAX is divisible by 16 */
        do {
            DO16(buf);          /* 16 sums unrolled */
            buf += 16;
        } while (--n);
        MOD(adler);
        MOD(sum2);
    }

    /* do remaining bytes (less than NMAX, still just one modulo) */
    if (len) {                  /* avoid modulos if none remaining */
        while (len >= 16) {
            len -= 16;
            DO16(buf);
            buf += 16;
        }
        while (len--) {
            adler += *buf++;
            sum2 += adler;
        }
        MOD(adler);
        MOD(sum2);
    }

    /* return recombined sums */
    return adler | (sum2 << 16);
}

uLong ZEXPORT adler32_combine(
    uLong adler1,
    uLong adler2,
    z_off_t len2)
{
    unsigned long sum1;
    unsigned long sum2;
    unsigned rem;

    /* the derivation of this formula is left as an exercise for the reader */
    rem = (unsigned)(len2 % BASE);
    sum1 = adler1 & 0xffff;
    sum2 = rem * sum1;
    MOD(sum2);
    sum1 += (adler2 & 0xffff) + BASE - 1;
    sum2 += ((adler1 >> 16) & 0xffff) + ((adler2 >> 16) & 0xffff) + BASE - rem;
    if (sum1 > BASE) sum1 -= BASE;
    if (sum1 > BASE) sum1 -= BASE;
    if (sum2 > (BASE << 1)) sum2 -= (BASE << 1);
    if (sum2 > BASE) sum2 -= BASE;
    return sum1 | (sum2 << 16);
}

     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
   Z_STREAM_ERROR if the level parameter is invalid.
*/
int ZEXPORT compress2 (
    Bytef *dest,
    uLongf *destLen,
    const Bytef *source,
    uLong sourceLen,
    int level)
{
    z_stream stream;
    int err;

    stream.next_in = (Bytef*)source;
    stream.avail_in = (uInt)sourceLen;
#ifdef MAXSEG_64K
    /* Check for source > 64K on 16-bit machine: */
    if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
#endif
    stream.next_out = dest;
    stream.avail_out = (uInt)*destLen;
    if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;

    stream.zalloc = (alloc_func)0;
    stream.zfree = (free_func)0;
    stream.opaque = (voidpf)0;

    err = deflateInit(&stream, level);
    if (err != Z_OK) return err;

    err = deflate(&stream, Z_FINISH);
    if (err != Z_STREAM_END) {
        deflateEnd(&stream);
        return err == Z_OK ? Z_BUF_ERROR : err;
    }
    *destLen = stream.total_out;

    err = deflateEnd(&stream);
    return err;
}

int ZEXPORT compress (
    Bytef *dest,
    uLongf *destLen,
    const Bytef *source,
    uLong sourceLen)
{
    return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
}

uLong ZEXPORT compressBound (
    uLong sourceLen)
{
    return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + 11;
}

  The first table is simply the CRC of all possible eight bit values.  This is
  all the information needed to generate CRCs on data a byte at a time for all
  combinations of CRC register values and incoming bytes.  The remaining tables
  allow for word-at-a-time CRC calculation for both big-endian and little-
  endian machines, where a word is four bytes.
*/
local void make_crc_table( void )
{
    unsigned long c;
    int n, k;
    unsigned long poly;                 /* polynomial exclusive-or pattern */
    /* terms of polynomial defining this crc (except x^32): */
    static volatile int first = 1;      /* flag to limit concurrent making */
    static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};

    /* See if another task is already doing this (not thread-safe, but better
       than nothing -- significantly reduces duration of vulnerability in
       case the advice about DYNAMIC_CRC_TABLE is ignored) */
    if (first) {
        first = 0;

        /* make exclusive-or pattern from polynomial (0xedb88320UL) */
        poly = 0UL;
        for (n = 0; n < sizeof(p)/sizeof(unsigned char); n++)
            poly |= 1UL << (31 - p[n]);

        /* generate a crc for every 8-bit value */
        for (n = 0; n < 256; n++) {
            c = (unsigned long)n;
            for (k = 0; k < 8; k++)
                c = c & 1 ? poly ^ (c >> 1) : c >> 1;
            crc_table[0][n] = c;
        }

#ifdef BYFOUR
        /* generate crc for each value followed by one, two, and three zeros,
           and then the byte reversal of those as well as the first table */
        for (n = 0; n < 256; n++) {
            c = crc_table[0][n];
            crc_table[4][n] = REV(c);
            for (k = 1; k < 4; k++) {
                c = crc_table[0][c & 0xff] ^ (c >> 8);
                crc_table[k][n] = c;
                crc_table[k + 4][n] = REV(c);
            }
        }
#endif /* BYFOUR */

        crc_table_empty = 0;
    }
    else {      /* not first */
        /* wait for the other guy to finish (not efficient, but rare) */
        while (crc_table_empty)
            ;
    }

#ifdef MAKECRCH
    /* write out CRC tables to crc32.h */
    {
        FILE *out;

        out = fopen("crc32.h", "w");
        if (out == NULL) return;
        fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n");
        fprintf(out, " * Generated automatically by crc32.c\n */\n\n");
        fprintf(out, "local const unsigned long FAR ");
        fprintf(out, "crc_table[TBLS][256] =\n{\n  {\n");
        write_table(out, crc_table[0]);
#  ifdef BYFOUR
        fprintf(out, "#ifdef BYFOUR\n");
        for (k = 1; k < 8; k++) {
            fprintf(out, "  },\n  {\n");
            write_table(out, crc_table[k]);
        }
        fprintf(out, "#endif\n");
#  endif /* BYFOUR */
        fprintf(out, "  }\n};\n");
        fclose(out);
    }
#endif /* MAKECRCH */
}

local void write_table(
    FILE *out,
    const unsigned long FAR *table)
{
    int n;

    for (n = 0; n < 256; n++)
        fprintf(out, "%s0x%08lxUL%s", n % 5 ? "" : "    ", table[n],
                n == 255 ? "\n" : (n % 5 == 4 ? ",\n" : ", "));
}

const unsigned long FAR * ZEXPORT get_crc_table( void )
{
#ifdef DYNAMIC_CRC_TABLE
    if (crc_table_empty)
        make_crc_table();
#endif /* DYNAMIC_CRC_TABLE */
    return (const unsigned long FAR *)crc_table;
}

unsigned long ZEXPORT crc32(
    unsigned long crc,
    const unsigned char FAR *buf,
    unsigned len)
{
    if (buf == Z_NULL) return 0UL;

#ifdef DYNAMIC_CRC_TABLE
    if (crc_table_empty)
        make_crc_table();
#endif /* DYNAMIC_CRC_TABLE */

#ifdef BYFOUR
    if (sizeof(void *) == sizeof(ptrdiff_t)) {
        u4 endian;

        endian = 1;
        if (*((unsigned char *)(&endian)))
            return crc32_little(crc, buf, len);
        else
            return crc32_big(crc, buf, len);
    }
#endif /* BYFOUR */
    crc = crc ^ 0xffffffffUL;
    while (len >= 8) {
        DO8;
        len -= 8;
    }
    if (len) do {
        DO1;
    } while (--len);
    return crc ^ 0xffffffffUL;
}

#ifdef BYFOUR

/* ========================================================================= */
#define DOLIT4 c ^= *buf4++; \
        c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \
            crc_table[1][(c >> 16) & 0xff] ^ crc_table[0][c >> 24]

local unsigned long crc32_little(
    unsigned long crc,
    const unsigned char FAR *buf,
    unsigned len)
{
    register u4 c;
    register const u4 FAR *buf4;

    c = (u4)crc;
    c = ~c;
    while (len && ((ptrdiff_t)buf & 3)) {
        c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
        len--;
    }

    buf4 = (const u4 FAR *)(const void FAR *)buf;
    while (len >= 32) {
        DOLIT32;
        len -= 32;
    }
    while (len >= 4) {
        DOLIT4;
        len -= 4;
    }
    buf = (const unsigned char FAR *)buf4;

    if (len) do {
        c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
    } while (--len);
    c = ~c;
    return (unsigned long)c;
}

/* ========================================================================= */
#define DOBIG4 c ^= *++buf4; \
        c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \
            crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24]

local unsigned long crc32_big(
    unsigned long crc,
    const unsigned char FAR *buf,
    unsigned len)
{
    register u4 c;
    register const u4 FAR *buf4;

    c = REV((u4)crc);
    c = ~c;
    while (len && ((ptrdiff_t)buf & 3)) {
        c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
        len--;
    }

    buf4 = (const u4 FAR *)(const void FAR *)buf;
    buf4--;
    while (len >= 32) {
        DOBIG32;
        len -= 32;
    }
    while (len >= 4) {
        DOBIG4;
        len -= 4;
    }
    buf4++;
    buf = (const unsigned char FAR *)buf4;

    if (len) do {
        c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
    } while (--len);
    c = ~c;
    return (unsigned long)(REV(c));
}

local unsigned long gf2_matrix_times(
    unsigned long *mat,
    unsigned long vec)
{
    unsigned long sum;

    sum = 0;
    while (vec) {
        if (vec & 1)
            sum ^= *mat;
        vec >>= 1;
        mat++;
    }
    return sum;
}

local void gf2_matrix_square(
    unsigned long *square,
    unsigned long *mat)
{
    int n;

    for (n = 0; n < GF2_DIM; n++)
        square[n] = gf2_matrix_times(mat, mat[n]);
}

uLong ZEXPORT crc32_combine(
    uLong crc1,
    uLong crc2,
    z_off_t len2)
{
    int n;
    unsigned long row;
    unsigned long even[GF2_DIM];    /* even-power-of-two zeros operator */
    unsigned long odd[GF2_DIM];     /* odd-power-of-two zeros operator */

    /* degenerate case */
    if (len2 == 0)
        return crc1;

    /* put operator for one zero bit in odd */
    odd[0] = 0xedb88320L;           /* CRC-32 polynomial */
    row = 1;
    for (n = 1; n < GF2_DIM; n++) {
        odd[n] = row;
        row <<= 1;
    }

    /* put operator for two zero bits in even */
    gf2_matrix_square(even, odd);

    /* put operator for four zero bits in odd */
    gf2_matrix_square(odd, even);

    /* apply len2 zeros to crc1 (first square will put the operator for one
       zero byte, eight zero bits, in even) */
    do {
        /* apply zeros operator for this bit of len2 */
        gf2_matrix_square(even, odd);
        if (len2 & 1)
            crc1 = gf2_matrix_times(even, crc1);
        len2 >>= 1;

        /* if no more bits set, then done */
        if (len2 == 0)
            break;

        /* another iteration of the loop with odd and even swapped */
        gf2_matrix_square(odd, even);
        if (len2 & 1)
            crc1 = gf2_matrix_times(odd, crc1);
        len2 >>= 1;

        /* if no more bits set, then done */
    } while (len2 != 0);

    /* return combined crc */
    crc1 ^= crc2;
    return crc1;
}

int ZEXPORT deflateInit_(
    z_streamp strm,
    int level,
    const char *version,
    int stream_size)
{
    return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
                         Z_DEFAULT_STRATEGY, version, stream_size);
    /* To do: ignore strm->next_in if we use it as window */
}

int ZEXPORT deflateInit2_(
    z_streamp strm,
    int  level,
    int  method,
    int  windowBits,
    int  memLevel,
    int  strategy,
    const char *version,
    int stream_size)
{
    deflate_state *s;
    int wrap = 1;
    static const char my_version[] = ZLIB_VERSION;

    ushf *overlay;
    /* We overlay pending_buf and d_buf+l_buf. This works since the average
     * output size for (length,distance) codes is <= 24 bits.
     */

    if (version == Z_NULL || version[0] != my_version[0] ||
        stream_size != sizeof(z_stream)) {
        return Z_VERSION_ERROR;
    }
    if (strm == Z_NULL) return Z_STREAM_ERROR;

    strm->msg = Z_NULL;
    if (strm->zalloc == (alloc_func)0) {
        strm->zalloc = zcalloc;
        strm->opaque = (voidpf)0;
    }
    if (strm->zfree == (free_func)0) strm->zfree = zcfree;

#ifdef FASTEST
    if (level != 0) level = 1;
#else
    if (level == Z_DEFAULT_COMPRESSION) level = 6;
#endif

    if (windowBits < 0) { /* suppress zlib wrapper */
        wrap = 0;
        windowBits = -windowBits;
    }
#ifdef GZIP
    else if (windowBits > 15) {
        wrap = 2;       /* write gzip wrapper instead */
        windowBits -= 16;
    }
#endif
    if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
        windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
        strategy < 0 || strategy > Z_FIXED) {
        return Z_STREAM_ERROR;
    }
    if (windowBits == 8) windowBits = 9;  /* until 256-byte window bug fixed */
    s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
    if (s == Z_NULL) return Z_MEM_ERROR;
    strm->state = (struct internal_state FAR *)s;
    s->strm = strm;

    s->wrap = wrap;
    s->gzhead = Z_NULL;
    s->w_bits = windowBits;
    s->w_size = 1 << s->w_bits;
    s->w_mask = s->w_size - 1;

    s->hash_bits = memLevel + 7;
    s->hash_size = 1 << s->hash_bits;
    s->hash_mask = s->hash_size - 1;
    s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);

    s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
    s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
    s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));

    s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */

    overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
    s->pending_buf = (uchf *) overlay;
    s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);

    if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
        s->pending_buf == Z_NULL) {
        s->status = FINISH_STATE;
        strm->msg = (char*)ERR_MSG(Z_MEM_ERROR);
        deflateEnd (strm);
        return Z_MEM_ERROR;
    }
    s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
    s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;

    s->level = level;
    s->strategy = strategy;
    s->method = (Byte)method;

    return deflateReset(strm);
}

int ZEXPORT deflateSetDictionary (
    z_streamp strm,
    const Bytef *dictionary,
    uInt  dictLength)
{
    deflate_state *s;
    uInt length = dictLength;
    uInt n;
    IPos hash_head = 0;

    if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL ||
        strm->state->wrap == 2 ||
        (strm->state->wrap == 1 && strm->state->status != INIT_STATE))
        return Z_STREAM_ERROR;

    s = strm->state;
    if (s->wrap)
        strm->adler = adler32(strm->adler, dictionary, dictLength);

    if (length < MIN_MATCH) return Z_OK;
    if (length > MAX_DIST(s)) {
        length = MAX_DIST(s);
        dictionary += dictLength - length; /* use the tail of the dictionary */
    }
    zmemcpy(s->window, dictionary, length);
    s->strstart = length;
    s->block_start = (long)length;

    /* Insert all strings in the hash table (except for the last two bytes).
     * s->lookahead stays null, so s->ins_h will be recomputed at the next
     * call of fill_window.
     */
    s->ins_h = s->window[0];
    UPDATE_HASH(s, s->ins_h, s->window[1]);
    for (n = 0; n <= length - MIN_MATCH; n++) {
        INSERT_STRING(s, n, hash_head);
    }
    if (hash_head) {;}   /* to make compiler happy */
    return Z_OK;
}

int ZEXPORT deflateReset (
    z_streamp strm)
{
    deflate_state *s;

    if (strm == Z_NULL || strm->state == Z_NULL ||
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) {
        return Z_STREAM_ERROR;
    }

    strm->total_in = strm->total_out = 0;
    strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
    strm->data_type = Z_UNKNOWN;

    s = (deflate_state *)strm->state;
    s->pending = 0;
    s->pending_out = s->pending_buf;

    if (s->wrap < 0) {
        s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
    }
    s->status = s->wrap ? INIT_STATE : BUSY_STATE;
    strm->adler =
#ifdef GZIP
        s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
#endif
        adler32(0L, Z_NULL, 0);
    s->last_flush = Z_NO_FLUSH;

    _tr_init(s);
    lm_init(s);

    return Z_OK;
}

int ZEXPORT deflateSetHeader (
    z_streamp strm,
    gz_headerp head)
{
    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    if (strm->state->wrap != 2) return Z_STREAM_ERROR;
    strm->state->gzhead = head;
    return Z_OK;
}

int ZEXPORT deflatePrime (
    z_streamp strm,
    int bits,
    int value)
{
    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    strm->state->bi_valid = bits;
    strm->state->bi_buf = (ush)(value & ((1 << bits) - 1));
    return Z_OK;
}

int ZEXPORT deflateParams(
    z_streamp strm,
    int level,
    int strategy)
{
    deflate_state *s;
    compress_func func;
    int err = Z_OK;

    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    s = strm->state;

#ifdef FASTEST
    if (level != 0) level = 1;
#else
    if (level == Z_DEFAULT_COMPRESSION) level = 6;
#endif
    if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
        return Z_STREAM_ERROR;
    }
    func = configuration_table[s->level].func;

    if (func != configuration_table[level].func && strm->total_in != 0) {
        /* Flush the last buffer: */
        err = deflate(strm, Z_PARTIAL_FLUSH);
    }
    if (s->level != level) {
        s->level = level;
        s->max_lazy_match   = configuration_table[level].max_lazy;
        s->good_match       = configuration_table[level].good_length;
        s->nice_match       = configuration_table[level].nice_length;
        s->max_chain_length = configuration_table[level].max_chain;
    }
    s->strategy = strategy;
    return err;
}

int ZEXPORT deflateTune(
    z_streamp strm,
    int good_length,
    int max_lazy,
    int nice_length,
    int max_chain)
{
    deflate_state *s;

    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    s = strm->state;
    s->good_match = good_length;
    s->max_lazy_match = max_lazy;
    s->nice_match = nice_length;
    s->max_chain_length = max_chain;
    return Z_OK;
}

uLong ZEXPORT deflateBound(
    z_streamp strm,
    uLong sourceLen)
{
    deflate_state *s;
    uLong destLen;

    /* conservative upper bound */
    destLen = sourceLen +
              ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 11;

    /* if can't get parameters, return conservative bound */
    if (strm == Z_NULL || strm->state == Z_NULL)
        return destLen;

    /* if not default parameters, return conservative bound */
    s = strm->state;
    if (s->w_bits != 15 || s->hash_bits != 8 + 7)
        return destLen;

    /* default settings: return tight bound for that case */
    return compressBound(sourceLen);
}

local void putShortMSB (
    deflate_state *s,
    uInt b)
{
    put_byte(s, (Byte)(b >> 8));
    put_byte(s, (Byte)(b & 0xff));
}

local void flush_pending(
    z_streamp strm)
{
    unsigned len = strm->state->pending;

    if (len > strm->avail_out) len = strm->avail_out;
    if (len == 0) return;

    zmemcpy(strm->next_out, strm->state->pending_out, len);
    strm->next_out  += len;
    strm->state->pending_out  += len;
    strm->total_out += len;
    strm->avail_out  -= len;
    strm->state->pending -= len;
    if (strm->state->pending == 0) {
        strm->state->pending_out = strm->state->pending_buf;
    }
}

int ZEXPORT deflate (
    z_streamp strm,
    int flush)
{
    int old_flush; /* value of flush param for previous deflate call */
    deflate_state *s;

    if (strm == Z_NULL || strm->state == Z_NULL ||
        flush > Z_FINISH || flush < 0) {
        return Z_STREAM_ERROR;
    }
    s = strm->state;

    if (strm->next_out == Z_NULL ||
        (strm->next_in == Z_NULL && strm->avail_in != 0) ||
        (s->status == FINISH_STATE && flush != Z_FINISH)) {
        ERR_RETURN(strm, Z_STREAM_ERROR);
    }
    if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);

    s->strm = strm; /* just in case */
    old_flush = s->last_flush;
    s->last_flush = flush;

    /* Write the header */
    if (s->status == INIT_STATE) {
#ifdef GZIP
        if (s->wrap == 2) {
            strm->adler = crc32(0L, Z_NULL, 0);
            put_byte(s, 31);
            put_byte(s, 139);
            put_byte(s, 8);
            if (s->gzhead == NULL) {
                put_byte(s, 0);
                put_byte(s, 0);
                put_byte(s, 0);
                put_byte(s, 0);
                put_byte(s, 0);
                put_byte(s, s->level == 9 ? 2 :
                            (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
                             4 : 0));
                put_byte(s, OS_CODE);
                s->status = BUSY_STATE;
            }
            else {
                put_byte(s, (s->gzhead->text ? 1 : 0) +
                            (s->gzhead->hcrc ? 2 : 0) +
                            (s->gzhead->extra == Z_NULL ? 0 : 4) +
                            (s->gzhead->name == Z_NULL ? 0 : 8) +
                            (s->gzhead->comment == Z_NULL ? 0 : 16)
                        );
                put_byte(s, (Byte)(s->gzhead->time & 0xff));
                put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
                put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
                put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
                put_byte(s, s->level == 9 ? 2 :
                            (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
                             4 : 0));
                put_byte(s, s->gzhead->os & 0xff);
                if (s->gzhead->extra != NULL) {
                    put_byte(s, s->gzhead->extra_len & 0xff);
                    put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
                }
                if (s->gzhead->hcrc)
                    strm->adler = crc32(strm->adler, s->pending_buf,
                                        s->pending);
                s->gzindex = 0;
                s->status = EXTRA_STATE;
            }
        }
        else
#endif
        {
            uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
            uInt level_flags;

            if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
                level_flags = 0;
            else if (s->level < 6)
                level_flags = 1;
            else if (s->level == 6)
                level_flags = 2;
            else
                level_flags = 3;
            header |= (level_flags << 6);
            if (s->strstart != 0) header |= PRESET_DICT;
            header += 31 - (header % 31);

            s->status = BUSY_STATE;
            putShortMSB(s, header);

            /* Save the adler32 of the preset dictionary: */
            if (s->strstart != 0) {
                putShortMSB(s, (uInt)(strm->adler >> 16));
                putShortMSB(s, (uInt)(strm->adler & 0xffff));
            }
            strm->adler = adler32(0L, Z_NULL, 0);
        }
    }
#ifdef GZIP
    if (s->status == EXTRA_STATE) {
        if (s->gzhead->extra != NULL) {
            uInt beg = s->pending;  /* start of bytes to update crc */

            while (s->gzindex < (s->gzhead->extra_len & 0xffff)) {
                if (s->pending == s->pending_buf_size) {
                    if (s->gzhead->hcrc && s->pending > beg)
                        strm->adler = crc32(strm->adler, s->pending_buf + beg,
                                            s->pending - beg);
                    flush_pending(strm);
                    beg = s->pending;
                    if (s->pending == s->pending_buf_size)
                        break;
                }
                put_byte(s, s->gzhead->extra[s->gzindex]);
                s->gzindex++;
            }
            if (s->gzhead->hcrc && s->pending > beg)
                strm->adler = crc32(strm->adler, s->pending_buf + beg,
                                    s->pending - beg);
            if (s->gzindex == s->gzhead->extra_len) {
                s->gzindex = 0;
                s->status = NAME_STATE;
            }
        }
        else
            s->status = NAME_STATE;
    }
    if (s->status == NAME_STATE) {
        if (s->gzhead->name != NULL) {
            uInt beg = s->pending;  /* start of bytes to update crc */
            int val;

            do {
                if (s->pending == s->pending_buf_size) {
                    if (s->gzhead->hcrc && s->pending > beg)
                        strm->adler = crc32(strm->adler, s->pending_buf + beg,
                                            s->pending - beg);
                    flush_pending(strm);
                    beg = s->pending;
                    if (s->pending == s->pending_buf_size) {
                        val = 1;
                        break;
                    }
                }
                val = s->gzhead->name[s->gzindex++];
                put_byte(s, val);
            } while (val != 0);
            if (s->gzhead->hcrc && s->pending > beg)
                strm->adler = crc32(strm->adler, s->pending_buf + beg,
                                    s->pending - beg);
            if (val == 0) {
                s->gzindex = 0;
                s->status = COMMENT_STATE;
            }
        }
        else
            s->status = COMMENT_STATE;
    }
    if (s->status == COMMENT_STATE) {
        if (s->gzhead->comment != NULL) {
            uInt beg = s->pending;  /* start of bytes to update crc */
            int val;

            do {
                if (s->pending == s->pending_buf_size) {
                    if (s->gzhead->hcrc && s->pending > beg)
                        strm->adler = crc32(strm->adler, s->pending_buf + beg,
                                            s->pending - beg);
                    flush_pending(strm);
                    beg = s->pending;
                    if (s->pending == s->pending_buf_size) {
                        val = 1;
                        break;
                    }
                }
                val = s->gzhead->comment[s->gzindex++];
                put_byte(s, val);
            } while (val != 0);
            if (s->gzhead->hcrc && s->pending > beg)
                strm->adler = crc32(strm->adler, s->pending_buf + beg,
                                    s->pending - beg);
            if (val == 0)
                s->status = HCRC_STATE;
        }
        else
            s->status = HCRC_STATE;
    }
    if (s->status == HCRC_STATE) {
        if (s->gzhead->hcrc) {
            if (s->pending + 2 > s->pending_buf_size)
                flush_pending(strm);
            if (s->pending + 2 <= s->pending_buf_size) {
                put_byte(s, (Byte)(strm->adler & 0xff));
                put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
                strm->adler = crc32(0L, Z_NULL, 0);
                s->status = BUSY_STATE;
            }
        }
        else
            s->status = BUSY_STATE;
    }
#endif

    /* Flush as much pending output as possible */
    if (s->pending != 0) {
        flush_pending(strm);
        if (strm->avail_out == 0) {
            /* Since avail_out is 0, deflate will be called again with
             * more output space, but possibly with both pending and
             * avail_in equal to zero. There won't be anything to do,
             * but this is not an error situation so make sure we
             * return OK instead of BUF_ERROR at next call of deflate:
             */
            s->last_flush = -1;
            return Z_OK;
        }

    /* Make sure there is something to do and avoid duplicate consecutive
     * flushes. For repeated and useless calls with Z_FINISH, we keep
     * returning Z_STREAM_END instead of Z_BUF_ERROR.
     */
    } else if (strm->avail_in == 0 && flush <= old_flush &&
               flush != Z_FINISH) {
        ERR_RETURN(strm, Z_BUF_ERROR);
    }

    /* User must not provide more input after the first FINISH: */
    if (s->status == FINISH_STATE && strm->avail_in != 0) {
        ERR_RETURN(strm, Z_BUF_ERROR);
    }

    /* Start a new block or continue the current one.
     */
    if (strm->avail_in != 0 || s->lookahead != 0 ||
        (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
        block_state bstate;

        bstate = (*(configuration_table[s->level].func))(s, flush);

        if (bstate == finish_started || bstate == finish_done) {
            s->status = FINISH_STATE;
        }
        if (bstate == need_more || bstate == finish_started) {
            if (strm->avail_out == 0) {
                s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
            }
            return Z_OK;
            /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
             * of deflate should use the same flush parameter to make sure
             * that the flush is complete. So we don't have to output an
             * empty block here, this will be done at next call. This also
             * ensures that for a very small output buffer, we emit at most
             * one empty block.
             */
        }
        if (bstate == block_done) {
            if (flush == Z_PARTIAL_FLUSH) {
                _tr_align(s);
            } else { /* FULL_FLUSH or SYNC_FLUSH */
                _tr_stored_block(s, (char*)0, 0L, 0);
                /* For a full flush, this empty block will be recognized
                 * as a special marker by inflate_sync().
                 */
                if (flush == Z_FULL_FLUSH) {
                    CLEAR_HASH(s);             /* forget history */
                }
            }
            flush_pending(strm);
            if (strm->avail_out == 0) {
              s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
              return Z_OK;
            }
        }
    }
    Assert(strm->avail_out > 0, "bug2");

    if (flush != Z_FINISH) return Z_OK;
    if (s->wrap <= 0) return Z_STREAM_END;

    /* Write the trailer */
#ifdef GZIP
    if (s->wrap == 2) {
        put_byte(s, (Byte)(strm->adler & 0xff));
        put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
        put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
        put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
        put_byte(s, (Byte)(strm->total_in & 0xff));
        put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
        put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
        put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
    }
    else
#endif
    {
        putShortMSB(s, (uInt)(strm->adler >> 16));
        putShortMSB(s, (uInt)(strm->adler & 0xffff));
    }
    flush_pending(strm);
    /* If avail_out is zero, the application will call deflate again
     * to flush the rest.
     */
    if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
    return s->pending != 0 ? Z_OK : Z_STREAM_END;
}

int ZEXPORT deflateEnd (
    z_streamp strm)
{
    int status;

    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;

    status = strm->state->status;
    if (status != INIT_STATE &&
        status != EXTRA_STATE &&
        status != NAME_STATE &&
        status != COMMENT_STATE &&
        status != HCRC_STATE &&
        status != BUSY_STATE &&
        status != FINISH_STATE) {
      return Z_STREAM_ERROR;
    }

    /* Deallocate in reverse order of allocations: */
    TRY_FREE(strm, strm->state->pending_buf);
    TRY_FREE(strm, strm->state->head);
    TRY_FREE(strm, strm->state->prev);
    TRY_FREE(strm, strm->state->window);

    ZFREE(strm, strm->state);
    strm->state = Z_NULL;

    return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
}

int ZEXPORT deflateCopy (
    z_streamp dest,
    z_streamp source)
{
#ifdef MAXSEG_64K
    return Z_STREAM_ERROR;
#else
    deflate_state *ds;
    deflate_state *ss;
    ushf *overlay;


    if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
        return Z_STREAM_ERROR;
    }

    ss = source->state;

    zmemcpy(dest, source, sizeof(z_stream));

    ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
    if (ds == Z_NULL) return Z_MEM_ERROR;
    dest->state = (struct internal_state FAR *) ds;
    zmemcpy(ds, ss, sizeof(deflate_state));
    ds->strm = dest;

    ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
    ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
    ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
    overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
    ds->pending_buf = (uchf *) overlay;

    if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
        ds->pending_buf == Z_NULL) {
        deflateEnd (dest);
        return Z_MEM_ERROR;
    }
    /* following zmemcpy do not work for 16-bit MSDOS */
    zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
    zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
    zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
    zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);

    ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
    ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
    ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;

    ds->l_desc.dyn_tree = ds->dyn_ltree;
    ds->d_desc.dyn_tree = ds->dyn_dtree;
    ds->bl_desc.dyn_tree = ds->bl_tree;

    return Z_OK;
#endif /* MAXSEG_64K */
}

local int read_buf(
    z_streamp strm,
    Bytef *buf,
    unsigned size)
{
    unsigned len = strm->avail_in;

    if (len > size) len = size;
    if (len == 0) return 0;

    strm->avail_in  -= len;

    if (strm->state->wrap == 1) {
        strm->adler = adler32(strm->adler, strm->next_in, len);
    }
#ifdef GZIP
    else if (strm->state->wrap == 2) {
        strm->adler = crc32(strm->adler, strm->next_in, len);
    }
#endif
    zmemcpy(buf, strm->next_in, len);
    strm->next_in  += len;
    strm->total_in += len;

    return (int)len;
}

local void lm_init (
    deflate_state *s)
{
    s->window_size = (ulg)2L*s->w_size;

    CLEAR_HASH(s);

    /* Set the default configuration parameters:
     */
    s->max_lazy_match   = configuration_table[s->level].max_lazy;
    s->good_match       = configuration_table[s->level].good_length;
    s->nice_match       = configuration_table[s->level].nice_length;
    s->max_chain_length = configuration_table[s->level].max_chain;

    s->strstart = 0;
    s->block_start = 0L;
    s->lookahead = 0;
    s->match_length = s->prev_length = MIN_MATCH-1;
    s->match_available = 0;
    s->ins_h = 0;
#ifndef FASTEST
#ifdef ASMV
    match_init(); /* initialize the asm code */
#endif
#endif
}

local uInt longest_match(
    deflate_state *s,
    IPos cur_match)                             /* current match */
{
    unsigned chain_length = s->max_chain_length;/* max hash chain length */
    register Bytef *scan = s->window + s->strstart; /* current string */
    register Bytef *match;                       /* matched string */
    register int len;                           /* length of current match */
    int best_len = s->prev_length;              /* best match length so far */
    int nice_match = s->nice_match;             /* stop if match long enough */
    IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
        s->strstart - (IPos)MAX_DIST(s) : NIL;
    /* Stop when cur_match becomes <= limit. To simplify the code,
     * we prevent matches with the string of window index 0.
     */
    Posf *prev = s->prev;
    uInt wmask = s->w_mask;

#ifdef UNALIGNED_OK
    /* Compare two bytes at a time. Note: this is not always beneficial.
     * Try with and without -DUNALIGNED_OK to check.
     */
    register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
    register ush scan_start = *(ushf*)scan;
    register ush scan_end   = *(ushf*)(scan+best_len-1);
#else
    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
    register Byte scan_end1  = scan[best_len-1];
    register Byte scan_end   = scan[best_len];
#endif

    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
     * It is easy to get rid of this optimization if necessary.
     */
    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");

    /* Do not waste too much time if we already have a good match: */
    if (s->prev_length >= s->good_match) {
        chain_length >>= 2;
    }
    /* Do not look for matches beyond the end of the input. This is necessary
     * to make deflate deterministic.
     */
    if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;

    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");

    do {
        Assert(cur_match < s->strstart, "no future");
        match = s->window + cur_match;

        /* Skip to next match if the match length cannot increase
         * or if the match length is less than 2.  Note that the checks below
         * for insufficient lookahead only occur occasionally for performance
         * reasons.  Therefore uninitialized memory will be accessed, and
         * conditional jumps will be made that depend on those values.
         * However the length of the match is limited to the lookahead, so
         * the output of deflate is not affected by the uninitialized values.
         */
#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
        /* This code assumes sizeof(unsigned short) == 2. Do not use
         * UNALIGNED_OK if your compiler uses a different size.
         */
        if (*(ushf*)(match+best_len-1) != scan_end ||
            *(ushf*)match != scan_start) continue;

        /* It is not necessary to compare scan[2] and match[2] since they are
         * always equal when the other bytes match, given that the hash keys
         * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
         * strstart+3, +5, ... up to strstart+257. We check for insufficient
         * lookahead only every 4th comparison; the 128th check will be made
         * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
         * necessary to put more guard bytes at the end of the window, or
         * to check more often for insufficient lookahead.
         */
        Assert(scan[2] == match[2], "scan[2]?");
        scan++, match++;
        do {
        } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
                 scan < strend);
        /* The funny "do {}" generates better code on most compilers */

        /* Here, scan <= window+strstart+257 */
        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
        if (*scan == *match) scan++;

        len = (MAX_MATCH - 1) - (int)(strend-scan);
        scan = strend - (MAX_MATCH-1);

#else /* UNALIGNED_OK */

        if (match[best_len]   != scan_end  ||
            match[best_len-1] != scan_end1 ||
            *match            != *scan     ||
            *++match          != scan[1])      continue;

        /* The check at best_len-1 can be removed because it will be made
         * again later. (This heuristic is not always a win.)
         * It is not necessary to compare scan[2] and match[2] since they
         * are always equal when the other bytes match, given that
         * the hash keys are equal and that HASH_BITS >= 8.
         */
        scan += 2, match++;
        Assert(*scan == *match, "match[2]?");

        /* We check for insufficient lookahead only every 8th comparison;
         * the 256th check will be made at strstart+258.
         */
        do {
        } while (*++scan == *++match && *++scan == *++match &&
                 *++scan == *++match && *++scan == *++match &&
                 *++scan == *++match && *++scan == *++match &&
                 *++scan == *++match && *++scan == *++match &&
                 scan < strend);

        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");

        len = MAX_MATCH - (int)(strend - scan);
        scan = strend - MAX_MATCH;

#endif /* UNALIGNED_OK */

        if (len > best_len) {
            s->match_start = cur_match;
            best_len = len;
            if (len >= nice_match) break;
#ifdef UNALIGNED_OK
            scan_end = *(ushf*)(scan+best_len-1);
#else
            scan_end1  = scan[best_len-1];
            scan_end   = scan[best_len];
#endif
        }
    } while ((cur_match = prev[cur_match & wmask]) > limit
             && --chain_length != 0);

    if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
    return s->lookahead;
}

local uInt longest_match_fast(
    deflate_state *s,
    IPos cur_match)                             /* current match */
{
    register Bytef *scan = s->window + s->strstart; /* current string */
    register Bytef *match;                       /* matched string */
    register int len;                           /* length of current match */
    register Bytef *strend = s->window + s->strstart + MAX_MATCH;

    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
     * It is easy to get rid of this optimization if necessary.
     */
    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");

    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");

    Assert(cur_match < s->strstart, "no future");

    match = s->window + cur_match;

    /* Return failure if the match length is less than 2:
     */
    if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;

    /* The check at best_len-1 can be removed because it will be made
     * again later. (This heuristic is not always a win.)
     * It is not necessary to compare scan[2] and match[2] since they
     * are always equal when the other bytes match, given that
     * the hash keys are equal and that HASH_BITS >= 8.
     */
    scan += 2, match += 2;
    Assert(*scan == *match, "match[2]?");

    /* We check for insufficient lookahead only every 8th comparison;
     * the 256th check will be made at strstart+258.
     */
    do {
    } while (*++scan == *++match && *++scan == *++match &&
             *++scan == *++match && *++scan == *++match &&
             *++scan == *++match && *++scan == *++match &&
             *++scan == *++match && *++scan == *++match &&
             scan < strend);

    Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");

    len = MAX_MATCH - (int)(strend - scan);

    if (len < MIN_MATCH) return MIN_MATCH - 1;

    s->match_start = cur_match;
    return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
}

local void check_match(
    deflate_state *s,
    IPos start, match,
    int length)
{
    /* check that the match is indeed a match */
    if (zmemcmp(s->window + match,
                s->window + start, length) != EQUAL) {
        fprintf(stderr, " start %u, match %u, length %d\n",
                start, match, length);
        do {
            fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
        } while (--length != 0);
        z_error("invalid match");
    }
    if (z_verbose > 1) {
        fprintf(stderr,"\\[%d,%d]", start-match, length);
        do { putc(s->window[start++], stderr); } while (--length != 0);
    }
}

local void fill_window(
    deflate_state *s)
{
    register unsigned n, m;
    register Posf *p;
    unsigned more;    /* Amount of free space at the end of the window. */
    uInt wsize = s->w_size;

    do {
        more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);

        /* Deal with !@#$% 64K limit: */
#if defined( UINT_MAX ) && UINT_MAX <= 0xFFFF
        if (sizeof(int) <= 2) {
            if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
                more = wsize;

            } else if (more == (unsigned)(-1)) {
                /* Very unlikely, but possible on 16 bit machine if
                 * strstart == 0 && lookahead == 1 (input done a byte at time)
                 */
                more--;
            }
        }
#endif
        /* If the window is almost full and there is insufficient lookahead,
         * move the upper half to the lower one to make room in the upper half.
         */
        if (s->strstart >= wsize+MAX_DIST(s)) {

            zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
            s->match_start -= wsize;
            s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
            s->block_start -= (long) wsize;

            /* Slide the hash table (could be avoided with 32 bit values
               at the expense of memory usage). We slide even when level == 0
               to keep the hash table consistent if we switch back to level > 0
               later. (Using level 0 permanently is not an optimal usage of
               zlib, so we don't care about this pathological case.)
             */
            /* %%% avoid this when Z_RLE */
            n = s->hash_size;
            p = &s->head[n];
            do {
                m = *--p;
                *p = (Pos)(m >= wsize ? m-wsize : NIL);
            } while (--n);

            n = wsize;
#ifndef FASTEST
            p = &s->prev[n];
            do {
                m = *--p;
                *p = (Pos)(m >= wsize ? m-wsize : NIL);
                /* If n is not on any hash chain, prev[n] is garbage but
                 * its value will never be used.
                 */
            } while (--n);
#endif
            more += wsize;
        }
        if (s->strm->avail_in == 0) return;

        /* If there was no sliding:
         *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
         *    more == window_size - lookahead - strstart
         * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
         * => more >= window_size - 2*WSIZE + 2
         * In the BIG_MEM or MMAP case (not yet supported),
         *   window_size == input_size + MIN_LOOKAHEAD  &&
         *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
         * Otherwise, window_size == 2*WSIZE so more >= 2.
         * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
         */
        Assert(more >= 2, "more < 2");

        n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
        s->lookahead += n;

        /* Initialize the hash value now that we have some input: */
        if (s->lookahead >= MIN_MATCH) {
            s->ins_h = s->window[s->strstart];
            UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
#if MIN_MATCH != 3
            Call UPDATE_HASH() MIN_MATCH-3 more times
#endif
        }
        /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
         * but this is not important since only literal bytes will be emitted.
         */

    } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
}

/* ===========================================================================
 * Flush the current block, with given end-of-file flag.
 * IN assertion: strstart is set to the end of the current match.
 */
#define FLUSH_BLOCK_ONLY(s, eof) { \
   _tr_flush_block(s, (s->block_start >= 0L ? \
                   (charf *)&s->window[(unsigned)s->block_start] : \
                   (charf *)Z_NULL), \
                (ulg)((long)s->strstart - s->block_start), \
                (eof)); \
   s->block_start = s->strstart; \
   flush_pending(s->strm); \
   Tracev((stderr,"[FLUSH]")); \
}

/* Same but force premature exit if necessary. */
#define FLUSH_BLOCK(s, eof) { \
   FLUSH_BLOCK_ONLY(s, eof); \
   if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
}

local block_state deflate_stored(
    deflate_state *s,
    int flush)
{
    /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
     * to pending_buf_size, and each stored block has a 5 byte header:
     */
    ulg max_block_size = 0xffff;
    ulg max_start;

    if (max_block_size > s->pending_buf_size - 5) {
        max_block_size = s->pending_buf_size - 5;
    }

    /* Copy as much as possible from input to output: */
    for (;;) {
        /* Fill the window as much as possible: */
        if (s->lookahead <= 1) {

            Assert(s->strstart < s->w_size+MAX_DIST(s) ||
                   s->block_start >= (long)s->w_size, "slide too late");

            fill_window(s);
            if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;

            if (s->lookahead == 0) break; /* flush the current block */
        }
        Assert(s->block_start >= 0L, "block gone");

        s->strstart += s->lookahead;
        s->lookahead = 0;

        /* Emit a stored block if pending_buf will be full: */
        max_start = s->block_start + max_block_size;
        if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
            /* strstart == 0 is possible when wraparound on 16-bit machine */
            s->lookahead = (uInt)(s->strstart - max_start);
            s->strstart = (uInt)max_start;
            FLUSH_BLOCK(s, 0);
        }
        /* Flush if we may have to slide, otherwise block_start may become
         * negative and the data will be gone:
         */
        if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
            FLUSH_BLOCK(s, 0);
        }
    }
    FLUSH_BLOCK(s, flush == Z_FINISH);
    return flush == Z_FINISH ? finish_done : block_done;
}

local block_state deflate_fast(
    deflate_state *s,
    int flush)
{
    IPos hash_head = NIL; /* head of the hash chain */
    int bflush;           /* set if current block must be flushed */

    for (;;) {
        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes
         * for the next match, plus MIN_MATCH bytes to insert the
         * string following the next match.
         */
        if (s->lookahead < MIN_LOOKAHEAD) {
            fill_window(s);
            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
                return need_more;
            }
            if (s->lookahead == 0) break; /* flush the current block */
        }

        /* Insert the string window[strstart .. strstart+2] in the
         * dictionary, and set hash_head to the head of the hash chain:
         */
        if (s->lookahead >= MIN_MATCH) {
            INSERT_STRING(s, s->strstart, hash_head);
        }

        /* Find the longest match, discarding those <= prev_length.
         * At this point we have always match_length < MIN_MATCH
         */
        if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
            /* To simplify the code, we prevent matches with the string
             * of window index 0 (in particular we have to avoid a match
             * of the string with itself at the start of the input file).
             */
#ifdef FASTEST
            if ((s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) ||
                (s->strategy == Z_RLE && s->strstart - hash_head == 1)) {
                s->match_length = longest_match_fast (s, hash_head);
            }
#else
            if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) {
                s->match_length = longest_match (s, hash_head);
            } else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) {
                s->match_length = longest_match_fast (s, hash_head);
            }
#endif
            /* longest_match() or longest_match_fast() sets match_start */
        }
        if (s->match_length >= MIN_MATCH) {
            check_match(s, s->strstart, s->match_start, s->match_length);

            _tr_tally_dist(s, s->strstart - s->match_start,
                           s->match_length - MIN_MATCH, bflush);

            s->lookahead -= s->match_length;

            /* Insert new strings in the hash table only if the match length
             * is not too large. This saves time but degrades compression.
             */
#ifndef FASTEST
            if (s->match_length <= s->max_insert_length &&
                s->lookahead >= MIN_MATCH) {
                s->match_length--; /* string at strstart already in table */
                do {
                    s->strstart++;
                    INSERT_STRING(s, s->strstart, hash_head);
                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
                     * always MIN_MATCH bytes ahead.
                     */
                } while (--s->match_length != 0);
                s->strstart++;
            } else
#endif
            {
                s->strstart += s->match_length;
                s->match_length = 0;
                s->ins_h = s->window[s->strstart];
                UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
#if MIN_MATCH != 3
                Call UPDATE_HASH() MIN_MATCH-3 more times
#endif
                /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
                 * matter since it will be recomputed at next deflate call.
                 */
            }
        } else {
            /* No match, output a literal byte */
            Tracevv((stderr,"%c", s->window[s->strstart]));
            _tr_tally_lit (s, s->window[s->strstart], bflush);
            s->lookahead--;
            s->strstart++;
        }
        if (bflush) FLUSH_BLOCK(s, 0);
    }
    FLUSH_BLOCK(s, flush == Z_FINISH);
    return flush == Z_FINISH ? finish_done : block_done;
}

local block_state deflate_slow(
    deflate_state *s,
    int flush)
{
    IPos hash_head = NIL;    /* head of hash chain */
    int bflush;              /* set if current block must be flushed */

    /* Process the input block. */
    for (;;) {
        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes
         * for the next match, plus MIN_MATCH bytes to insert the
         * string following the next match.
         */
        if (s->lookahead < MIN_LOOKAHEAD) {
            fill_window(s);
            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
                return need_more;
            }
            if (s->lookahead == 0) break; /* flush the current block */
        }

        /* Insert the string window[strstart .. strstart+2] in the
         * dictionary, and set hash_head to the head of the hash chain:
         */
        if (s->lookahead >= MIN_MATCH) {
            INSERT_STRING(s, s->strstart, hash_head);
        }

        /* Find the longest match, discarding those <= prev_length.
         */
        s->prev_length = s->match_length, s->prev_match = s->match_start;
        s->match_length = MIN_MATCH-1;

        if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
            s->strstart - hash_head <= MAX_DIST(s)) {
            /* To simplify the code, we prevent matches with the string
             * of window index 0 (in particular we have to avoid a match
             * of the string with itself at the start of the input file).
             */
            if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) {
                s->match_length = longest_match (s, hash_head);
            } else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) {
                s->match_length = longest_match_fast (s, hash_head);
            }
            /* longest_match() or longest_match_fast() sets match_start */

            if (s->match_length <= 5 && (s->strategy == Z_FILTERED
#if TOO_FAR <= 32767
                || (s->match_length == MIN_MATCH &&
                    s->strstart - s->match_start > TOO_FAR)
#endif
                )) {

                /* If prev_match is also MIN_MATCH, match_start is garbage
                 * but we will ignore the current match anyway.
                 */
                s->match_length = MIN_MATCH-1;
            }
        }
        /* If there was a match at the previous step and the current
         * match is not better, output the previous match:
         */
        if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
            uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
            /* Do not insert strings in hash table beyond this. */

            check_match(s, s->strstart-1, s->prev_match, s->prev_length);

            _tr_tally_dist(s, s->strstart -1 - s->prev_match,
                           s->prev_length - MIN_MATCH, bflush);

            /* Insert in hash table all strings up to the end of the match.
             * strstart-1 and strstart are already inserted. If there is not
             * enough lookahead, the last two strings are not inserted in
             * the hash table.
             */
            s->lookahead -= s->prev_length-1;
            s->prev_length -= 2;
            do {
                if (++s->strstart <= max_insert) {
                    INSERT_STRING(s, s->strstart, hash_head);
                }
            } while (--s->prev_length != 0);
            s->match_available = 0;
            s->match_length = MIN_MATCH-1;
            s->strstart++;

            if (bflush) FLUSH_BLOCK(s, 0);

        } else if (s->match_available) {
            /* If there was no match at the previous position, output a
             * single literal. If there was a match but the current match
             * is longer, truncate the previous match to a single literal.
             */
            Tracevv((stderr,"%c", s->window[s->strstart-1]));
            _tr_tally_lit(s, s->window[s->strstart-1], bflush);
            if (bflush) {
                FLUSH_BLOCK_ONLY(s, 0);
            }
            s->strstart++;
            s->lookahead--;
            if (s->strm->avail_out == 0) return need_more;
        } else {
            /* There is no previous match to compare with, wait for
             * the next step to decide.
             */
            s->match_available = 1;
            s->strstart++;
            s->lookahead--;
        }
    }
    Assert (flush != Z_NO_FLUSH, "no flush?");
    if (s->match_available) {
        Tracevv((stderr,"%c", s->window[s->strstart-1]));
        _tr_tally_lit(s, s->window[s->strstart-1], bflush);
        (void)(bflush); /* pacify warning */
        s->match_available = 0;
    }
    FLUSH_BLOCK(s, flush == Z_FINISH);
    return flush == Z_FINISH ? finish_done : block_done;
}

local block_state deflate_rle(
    deflate_state *s,
    int flush)
{
    int bflush;         /* set if current block must be flushed */
    uInt run;           /* length of run */
    uInt max;           /* maximum length of run */
    uInt prev;          /* byte at distance one to match */
    Bytef *scan;        /* scan for end of run */

    for (;;) {
        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes
         * for the longest encodable run.
         */
        if (s->lookahead < MAX_MATCH) {
            fill_window(s);
            if (s->lookahead < MAX_MATCH && flush == Z_NO_FLUSH) {
                return need_more;
            }
            if (s->lookahead == 0) break; /* flush the current block */
        }

        /* See how many times the previous byte repeats */
        run = 0;
        if (s->strstart > 0) {      /* if there is a previous byte, that is */
            max = s->lookahead < MAX_MATCH ? s->lookahead : MAX_MATCH;
            scan = s->window + s->strstart - 1;
            prev = *scan++;
            do {
                if (*scan++ != prev)
                    break;
            } while (++run < max);
        }

        /* Emit match if have run of MIN_MATCH or longer, else emit literal */
        if (run >= MIN_MATCH) {
            check_match(s, s->strstart, s->strstart - 1, run);
            _tr_tally_dist(s, 1, run - MIN_MATCH, bflush);
            s->lookahead -= run;
            s->strstart += run;
        } else {
            /* No match, output a literal byte */
            Tracevv((stderr,"%c", s->window[s->strstart]));
            _tr_tally_lit (s, s->window[s->strstart], bflush);
            s->lookahead--;
            s->strstart++;
        }
        if (bflush) FLUSH_BLOCK(s, 0);
    }
    FLUSH_BLOCK(s, flush == Z_FINISH);
    return flush == Z_FINISH ? finish_done : block_done;
}

local gzFile gz_open (
    const char *path,
    const char *mode,
    int  fd)
{
    int err;
    int level = Z_DEFAULT_COMPRESSION; /* compression level */
    int strategy = Z_DEFAULT_STRATEGY; /* compression strategy */
    char *p = (char*)mode;
    gz_stream *s;
    char fmode[80]; /* copy of mode, without the compression level */
    char *m = fmode;

    if (!path || !mode) return Z_NULL;

    s = (gz_stream *)ALLOC(sizeof(gz_stream));
    if (!s) return Z_NULL;

    s->stream.zalloc = (alloc_func)0;
    s->stream.zfree = (free_func)0;
    s->stream.opaque = (voidpf)0;
    s->stream.next_in = s->inbuf = Z_NULL;
    s->stream.next_out = s->outbuf = Z_NULL;
    s->stream.avail_in = s->stream.avail_out = 0;
    s->file = NULL;
    s->z_err = Z_OK;
    s->z_eof = 0;
    s->in = 0;
    s->out = 0;
    s->back = EOF;
    s->crc = crc32(0L, Z_NULL, 0);
    s->msg = NULL;
    s->transparent = 0;

    s->path = (char*)ALLOC(strlen(path)+1);
    if (s->path == NULL) {
        return destroy(s), (gzFile)Z_NULL;
    }
    strcpy(s->path, path); /* do this early for debugging */

    s->mode = '\0';
    do {
        if (*p == 'r') s->mode = 'r';
        if (*p == 'w' || *p == 'a') s->mode = 'w';
        if (*p >= '0' && *p <= '9') {
            level = *p - '0';
        } else if (*p == 'f') {
          strategy = Z_FILTERED;
        } else if (*p == 'h') {
          strategy = Z_HUFFMAN_ONLY;
        } else if (*p == 'R') {
          strategy = Z_RLE;
        } else {
            *m++ = *p; /* copy the mode */
        }
    } while (*p++ && m != fmode + sizeof(fmode));
    if (s->mode == '\0') return destroy(s), (gzFile)Z_NULL;

    if (s->mode == 'w') {
#ifdef NO_GZCOMPRESS
        err = Z_STREAM_ERROR;
#else
        err = deflateInit2(&(s->stream), level,
                           Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, strategy);
        /* windowBits is passed < 0 to suppress zlib header */

        s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
#endif
        if (err != Z_OK || s->outbuf == Z_NULL) {
            return destroy(s), (gzFile)Z_NULL;
        }
    } else {
        s->stream.next_in  = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE);

        err = inflateInit2(&(s->stream), -MAX_WBITS);
        /* windowBits is passed < 0 to tell that there is no zlib header.
         * Note that in this case inflate *requires* an extra "dummy" byte
         * after the compressed stream in order to complete decompression and
         * return Z_STREAM_END. Here the gzip CRC32 ensures that 4 bytes are
         * present after the compressed stream.
         */
        if (err != Z_OK || s->inbuf == Z_NULL) {
            return destroy(s), (gzFile)Z_NULL;
        }
    }
    s->stream.avail_out = Z_BUFSIZE;

    errno = 0;
    s->file = fd < 0 ? F_OPEN(path, fmode) : (FILE*)fdopen(fd, fmode);

    if (s->file == NULL) {
        return destroy(s), (gzFile)Z_NULL;
    }
    if (s->mode == 'w') {
        /* Write a very simple .gz header:
         */
        fprintf(s->file, "%c%c%c%c%c%c%c%c%c%c", gz_magic[0], gz_magic[1],
             Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/, 0 /*xflags*/, OS_CODE);
        s->start = 10L;
        /* We use 10L instead of ftell(s->file) to because ftell causes an
         * fflush on some systems. This version of the library doesn't use
         * start anyway in write mode, so this initialization is not
         * necessary.
         */
    } else {
        check_header(s); /* skip the .gz header */
        s->start = ftell(s->file) - s->stream.avail_in;
    }

    return (gzFile)s;
}

gzFile ZEXPORT gzopen (
    const char *path,
    const char *mode)
{
    return gz_open (path, mode, -1);
}

gzFile ZEXPORT gzdopen (
    int fd,
    const char *mode)
{
    char name[46];      /* allow for up to 128-bit integers */

    if (fd < 0) return (gzFile)Z_NULL;
    sprintf(name, "", fd); /* for debugging */

    return gz_open (name, mode, fd);
}

int ZEXPORT gzsetparams (
    gzFile file,
    int level,
    int strategy)
{
    gz_stream *s = (gz_stream*)file;

    if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;

    /* Make room to allow flushing */
    if (s->stream.avail_out == 0) {

        s->stream.next_out = s->outbuf;
        if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) {
            s->z_err = Z_ERRNO;
        }
        s->stream.avail_out = Z_BUFSIZE;
    }

    return deflateParams (&(s->stream), level, strategy);
}

local int get_byte(
    gz_stream *s)
{
    if (s->z_eof) return EOF;
    if (s->stream.avail_in == 0) {
        errno = 0;
        s->stream.avail_in = (uInt)fread(s->inbuf, 1, Z_BUFSIZE, s->file);
        if (s->stream.avail_in == 0) {
            s->z_eof = 1;
            if (ferror(s->file)) s->z_err = Z_ERRNO;
            return EOF;
        }
        s->stream.next_in = s->inbuf;
    }
    s->stream.avail_in--;
    return *(s->stream.next_in)++;
}

local void check_header(
    gz_stream *s)
{
    int method; /* method byte */
    int flags;  /* flags byte */
    uInt len;
    int c;

    /* Assure two bytes in the buffer so we can peek ahead -- handle case
       where first byte of header is at the end of the buffer after the last
       gzip segment */
    len = s->stream.avail_in;
    if (len < 2) {
        if (len) s->inbuf[0] = s->stream.next_in[0];
        errno = 0;
        len = (uInt)fread(s->inbuf + len, 1, Z_BUFSIZE >> len, s->file);
        if (len == 0 && ferror(s->file)) s->z_err = Z_ERRNO;
        s->stream.avail_in += len;
        s->stream.next_in = s->inbuf;
        if (s->stream.avail_in < 2) {
            s->transparent = s->stream.avail_in;
            return;
        }
    }

    /* Peek ahead to check the gzip magic header */
    if (s->stream.next_in[0] != gz_magic[0] ||
        s->stream.next_in[1] != gz_magic[1]) {
        s->transparent = 1;
        return;
    }
    s->stream.avail_in -= 2;
    s->stream.next_in += 2;

    /* Check the rest of the gzip header */
    method = get_byte(s);
    flags = get_byte(s);
    if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
        s->z_err = Z_DATA_ERROR;
        return;
    }

    /* Discard time, xflags and OS code: */
    for (len = 0; len < 6; len++) (void)get_byte(s);

    if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
        len  =  (uInt)get_byte(s);
        len += ((uInt)get_byte(s))<<8;
        /* len is garbage if EOF but the loop below will quit anyway */
        while (len-- != 0 && get_byte(s) != EOF) ;
    }
    if ((flags & ORIG_NAME) != 0) { /* skip the original file name */
        while ((c = get_byte(s)) != 0 && c != EOF) ;
    }
    if ((flags & COMMENT) != 0) {   /* skip the .gz file comment */
        while ((c = get_byte(s)) != 0 && c != EOF) ;
    }
    if ((flags & HEAD_CRC) != 0) {  /* skip the header crc */
        for (len = 0; len < 2; len++) (void)get_byte(s);
    }
    s->z_err = s->z_eof ? Z_DATA_ERROR : Z_OK;
}

local int destroy (
    gz_stream *s)
{
    int err = Z_OK;

    if (!s) return Z_STREAM_ERROR;

    TRYFREE(s->msg);

    if (s->stream.state != NULL) {
        if (s->mode == 'w') {
#ifdef NO_GZCOMPRESS
            err = Z_STREAM_ERROR;
#else
            err = deflateEnd(&(s->stream));
#endif
        } else if (s->mode == 'r') {
            err = inflateEnd(&(s->stream));
        }
    }
    if (s->file != NULL && fclose(s->file)) {
#ifdef ESPIPE
        if (errno != ESPIPE) /* fclose is broken for pipes in HP/UX */
#endif
            err = Z_ERRNO;
    }
    if (s->z_err < 0) err = s->z_err;

    TRYFREE(s->inbuf);
    TRYFREE(s->outbuf);
    TRYFREE(s->path);
    TRYFREE(s);
    return err;
}

int ZEXPORT gzread (
    gzFile file,
    voidp buf,
    unsigned len)
{
    gz_stream *s = (gz_stream*)file;
    Bytef *start = (Bytef*)buf; /* starting point for crc computation */
    Byte  *next_out; /* == stream.next_out but not forced far (for MSDOS) */

    if (s == NULL || s->mode != 'r') return Z_STREAM_ERROR;

    if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) return -1;
    if (s->z_err == Z_STREAM_END) return 0;  /* EOF */

    next_out = (Byte*)buf;
    s->stream.next_out = (Bytef*)buf;
    s->stream.avail_out = len;

    if (s->stream.avail_out && s->back != EOF) {
        *next_out++ = s->back;
        s->stream.next_out++;
        s->stream.avail_out--;
        s->back = EOF;
        s->out++;
        start++;
        if (s->last) {
            s->z_err = Z_STREAM_END;
            return 1;
        }
    }

    while (s->stream.avail_out != 0) {

        if (s->transparent) {
            /* Copy first the lookahead bytes: */
            uInt n = s->stream.avail_in;
            if (n > s->stream.avail_out) n = s->stream.avail_out;
            if (n > 0) {
                zmemcpy(s->stream.next_out, s->stream.next_in, n);
                next_out += n;
                s->stream.next_out = next_out;
                s->stream.next_in   += n;
                s->stream.avail_out -= n;
                s->stream.avail_in  -= n;
            }
            if (s->stream.avail_out > 0) {
                s->stream.avail_out -=
                    (uInt)fread(next_out, 1, s->stream.avail_out, s->file);
            }
            len -= s->stream.avail_out;
            s->in  += len;
            s->out += len;
            if (len == 0) s->z_eof = 1;
            return (int)len;
        }
        if (s->stream.avail_in == 0 && !s->z_eof) {

            errno = 0;
            s->stream.avail_in = (uInt)fread(s->inbuf, 1, Z_BUFSIZE, s->file);
            if (s->stream.avail_in == 0) {
                s->z_eof = 1;
                if (ferror(s->file)) {
                    s->z_err = Z_ERRNO;
                    break;
                }
            }
            s->stream.next_in = s->inbuf;
        }
        s->in += s->stream.avail_in;
        s->out += s->stream.avail_out;
        s->z_err = inflate(&(s->stream), Z_NO_FLUSH);
        s->in -= s->stream.avail_in;
        s->out -= s->stream.avail_out;

        if (s->z_err == Z_STREAM_END) {
            /* Check CRC and original size */
            s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
            start = s->stream.next_out;

            if (getLong(s) != s->crc) {
                s->z_err = Z_DATA_ERROR;
            } else {
                (void)getLong(s);
                /* The uncompressed length returned by above getlong() may be
                 * different from s->out in case of concatenated .gz files.
                 * Check for such files:
                 */
                check_header(s);
                if (s->z_err == Z_OK) {
                    inflateReset(&(s->stream));
                    s->crc = crc32(0L, Z_NULL, 0);
                }
            }
        }
        if (s->z_err != Z_OK || s->z_eof) break;
    }
    s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));

    if (len == s->stream.avail_out &&
        (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO))
        return -1;
    return (int)(len - s->stream.avail_out);
}

int ZEXPORT gzgetc(
    gzFile file)
{
    unsigned char c;

    return gzread(file, &c, 1) == 1 ? c : -1;
}

int ZEXPORT gzungetc(
    int c,
    gzFile file)
{
    gz_stream *s = (gz_stream*)file;

    if (s == NULL || s->mode != 'r' || c == EOF || s->back != EOF) return EOF;
    s->back = c;
    s->out--;
    s->last = (s->z_err == Z_STREAM_END);
    if (s->last) s->z_err = Z_OK;
    s->z_eof = 0;
    return c;
}


/* ===========================================================================
      Reads bytes from the compressed file until len-1 characters are
   read, or a newline character is read and transferred to buf, or an
   end-of-file condition is encountered.  The string is then terminated
   with a null character.
      gzgets returns buf, or Z_NULL in case of error.

      The current implementation is not optimized at all.
*/
char * ZEXPORT gzgets(
    gzFile file,
    char *buf,
    int len)
{
    char *b = buf;
    if (buf == Z_NULL || len <= 0) return Z_NULL;

    while (--len > 0 && gzread(file, buf, 1) == 1 && *buf++ != '\n') ;
    *buf = '\0';
    return b == buf && len > 0 ? Z_NULL : b;
}

int ZEXPORT gzwrite (
    gzFile file,
    voidpc buf,
    unsigned len)
{
    gz_stream *s = (gz_stream*)file;

    if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;

    s->stream.next_in = (Bytef*)buf;
    s->stream.avail_in = len;

    while (s->stream.avail_in != 0) {

        if (s->stream.avail_out == 0) {

            s->stream.next_out = s->outbuf;
            if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) {
                s->z_err = Z_ERRNO;
                break;
            }
            s->stream.avail_out = Z_BUFSIZE;
        }
        s->in += s->stream.avail_in;
        s->out += s->stream.avail_out;
        s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
        s->in -= s->stream.avail_in;
        s->out -= s->stream.avail_out;
        if (s->z_err != Z_OK) break;
    }
    s->crc = crc32(s->crc, (const Bytef *)buf, len);

    return (int)(len - s->stream.avail_in);
}

int ZEXPORTVA gzprintf (gzFile file, const char *format, /* args */ ...)
{
    char buf[Z_PRINTF_BUFSIZE];
    va_list va;
    int len;

    buf[sizeof(buf) - 1] = 0;
    va_start(va, format);
#ifdef NO_vsnprintf
#  ifdef HAS_vsprintf_void
    (void)vsprintf(buf, format, va);
    va_end(va);
    for (len = 0; len < sizeof(buf); len++)
        if (buf[len] == 0) break;
#  else
    len = vsprintf(buf, format, va);
    va_end(va);
#  endif
#else
#  ifdef HAS_vsnprintf_void
    (void)vsnprintf(buf, sizeof(buf), format, va);
    va_end(va);
    len = strlen(buf);
#  else
    len = vsnprintf(buf, sizeof(buf), format, va);
    va_end(va);
#  endif
#endif
    if (len <= 0 || len >= (int)sizeof(buf) || buf[sizeof(buf) - 1] != 0)
        return 0;
    return gzwrite(file, buf, (unsigned)len);
}
#else /* not ANSI C */

int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
                       a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
    gzFile file;
    const char *format;
    int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
{
    char buf[Z_PRINTF_BUFSIZE];
    int len;

    buf[sizeof(buf) - 1] = 0;
#ifdef NO_snprintf
#  ifdef HAS_sprintf_void
    sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8,
            a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    for (len = 0; len < sizeof(buf); len++)
        if (buf[len] == 0) break;
#  else
    len = sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8,
                a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
#  endif
#else
#  ifdef HAS_snprintf_void
    snprintf(buf, sizeof(buf), format, a1, a2, a3, a4, a5, a6, a7, a8,
             a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    len = strlen(buf);
#  else
    len = snprintf(buf, sizeof(buf), format, a1, a2, a3, a4, a5, a6, a7, a8,
                 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
#  endif
#endif
    if (len <= 0 || len >= sizeof(buf) || buf[sizeof(buf) - 1] != 0)
        return 0;
    return gzwrite(file, buf, len);
}

int ZEXPORT gzputc(
    gzFile file,
    int c)
{
    unsigned char cc = (unsigned char) c; /* required for big endian systems */

    return gzwrite(file, &cc, 1) == 1 ? (int)cc : -1;
}

int ZEXPORT gzputs(
    gzFile file,
    const char *s)
{
    return gzwrite(file, (char*)s, (unsigned)strlen(s));
}

local int do_flush (
    gzFile file,
    int flush)
{
    uInt len;
    int done = 0;
    gz_stream *s = (gz_stream*)file;

    if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;

    s->stream.avail_in = 0; /* should be zero already anyway */

    for (;;) {
        len = Z_BUFSIZE - s->stream.avail_out;

        if (len != 0) {
            if ((uInt)fwrite(s->outbuf, 1, len, s->file) != len) {
                s->z_err = Z_ERRNO;
                return Z_ERRNO;
            }
            s->stream.next_out = s->outbuf;
            s->stream.avail_out = Z_BUFSIZE;
        }
        if (done) break;
        s->out += s->stream.avail_out;
        s->z_err = deflate(&(s->stream), flush);
        s->out -= s->stream.avail_out;

        /* Ignore the second of two consecutive flushes: */
        if (len == 0 && s->z_err == Z_BUF_ERROR) s->z_err = Z_OK;

        /* deflate has finished flushing only when it hasn't used up
         * all the available space in the output buffer:
         */
        done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END);

        if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break;
    }
    return  s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
}

int ZEXPORT gzflush (
     gzFile file,
     int flush)
{
    gz_stream *s = (gz_stream*)file;
    int err = do_flush (file, flush);

    if (err) return err;
    fflush(s->file);
    return  s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
}

z_off_t ZEXPORT gzseek (
    gzFile file,
    z_off_t offset,
    int whence)
{
    gz_stream *s = (gz_stream*)file;

    if (s == NULL || whence == SEEK_END ||
        s->z_err == Z_ERRNO || s->z_err == Z_DATA_ERROR) {
        return -1L;
    }

    if (s->mode == 'w') {
#ifdef NO_GZCOMPRESS
        return -1L;
#else
        if (whence == SEEK_SET) {
            offset -= s->in;
        }
        if (offset < 0) return -1L;

        /* At this point, offset is the number of zero bytes to write. */
        if (s->inbuf == Z_NULL) {
            s->inbuf = (Byte*)ALLOC(Z_BUFSIZE); /* for seeking */
            if (s->inbuf == Z_NULL) return -1L;
            zmemzero(s->inbuf, Z_BUFSIZE);
        }
        while (offset > 0)  {
            uInt size = Z_BUFSIZE;
            if (offset < Z_BUFSIZE) size = (uInt)offset;

            size = gzwrite(file, s->inbuf, size);
            if (size == 0) return -1L;

            offset -= size;
        }
        return s->in;
#endif
    }
    /* Rest of function is for reading only */

    /* compute absolute position */
    if (whence == SEEK_CUR) {
        offset += s->out;
    }
    if (offset < 0) return -1L;

    if (s->transparent) {
        /* map to fseek */
        s->back = EOF;
        s->stream.avail_in = 0;
        s->stream.next_in = s->inbuf;
        if (fseek(s->file, offset, SEEK_SET) < 0) return -1L;

        s->in = s->out = offset;
        return offset;
    }

    /* For a negative seek, rewind and use positive seek */
    if (offset >= s->out) {
        offset -= s->out;
    } else if (gzrewind(file) < 0) {
        return -1L;
    }
    /* offset is now the number of bytes to skip. */

    if (offset != 0 && s->outbuf == Z_NULL) {
        s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
        if (s->outbuf == Z_NULL) return -1L;
    }
    if (offset && s->back != EOF) {
        s->back = EOF;
        s->out++;
        offset--;
        if (s->last) s->z_err = Z_STREAM_END;
    }
    while (offset > 0)  {
        int size = Z_BUFSIZE;
        if (offset < Z_BUFSIZE) size = (int)offset;

        size = gzread(file, s->outbuf, (uInt)size);
        if (size <= 0) return -1L;
        offset -= size;
    }
    return s->out;
}

int ZEXPORT gzrewind (
    gzFile file)
{
    gz_stream *s = (gz_stream*)file;

    if (s == NULL || s->mode != 'r') return -1;

    s->z_err = Z_OK;
    s->z_eof = 0;
    s->back = EOF;
    s->stream.avail_in = 0;
    s->stream.next_in = s->inbuf;
    s->crc = crc32(0L, Z_NULL, 0);
    if (!s->transparent) (void)inflateReset(&s->stream);
    s->in = 0;
    s->out = 0;
    return fseek(s->file, s->start, SEEK_SET);
}

z_off_t ZEXPORT gztell (
    gzFile file)
{
    return gzseek(file, 0L, SEEK_CUR);
}

int ZEXPORT gzeof (
    gzFile file)
{
    gz_stream *s = (gz_stream*)file;

    /* With concatenated compressed files that can have embedded
     * crc trailers, z_eof is no longer the only/best indicator of EOF
     * on a gz_stream. Handle end-of-stream error explicitly here.
     */
    if (s == NULL || s->mode != 'r') return 0;
    if (s->z_eof) return 1;
    return s->z_err == Z_STREAM_END;
}

int ZEXPORT gzdirect (
    gzFile file)
{
    gz_stream *s = (gz_stream*)file;

    if (s == NULL || s->mode != 'r') return 0;
    return s->transparent;
}

local void putLong (
    FILE *file,
    uLong x)
{
    int n;
    for (n = 0; n < 4; n++) {
        fputc((int)(x & 0xff), file);
        x >>= 8;
    }
}

local uLong getLong (
    gz_stream *s)
{
    uLong x = (uLong)get_byte(s);
    int c;

    x += ((uLong)get_byte(s))<<8;
    x += ((uLong)get_byte(s))<<16;
    c = get_byte(s);
    if (c == EOF) s->z_err = Z_DATA_ERROR;
    x += ((uLong)c)<<24;
    return x;
}

int ZEXPORT gzclose (
    gzFile file)
{
    gz_stream *s = (gz_stream*)file;

    if (s == NULL) return Z_STREAM_ERROR;

    if (s->mode == 'w') {
#ifdef NO_GZCOMPRESS
        return Z_STREAM_ERROR;
#else
        if (do_flush (file, Z_FINISH) != Z_OK)
            return destroy((gz_stream*)file);

        putLong (s->file, s->crc);
        putLong (s->file, (uLong)(s->in & 0xffffffff));
#endif
    }
    return destroy((gz_stream*)file);
}

const char * ZEXPORT gzerror (
    gzFile file,
    int *errnum)
{
    char *m;
    gz_stream *s = (gz_stream*)file;

    if (s == NULL) {
        *errnum = Z_STREAM_ERROR;
        return (const char*)ERR_MSG(Z_STREAM_ERROR);
    }
    *errnum = s->z_err;
    if (*errnum == Z_OK) return (const char*)"";

    m = (char*)(*errnum == Z_ERRNO ? zstrerror(errno) : s->stream.msg);

    if (m == NULL || *m == '\0') m = (char*)ERR_MSG(s->z_err);

    TRYFREE(s->msg);
    s->msg = (char*)ALLOC(strlen(s->path) + strlen(m) + 3);
    if (s->msg == Z_NULL) return (const char*)ERR_MSG(Z_MEM_ERROR);
    strcpy(s->msg, s->path);
    strcat(s->msg, ": ");
    strcat(s->msg, m);
    return (const char*)s->msg;
}

void ZEXPORT gzclearerr (
    gzFile file)
{
    gz_stream *s = (gz_stream*)file;

    if (s == NULL) return;
    if (s->z_err != Z_STREAM_END) s->z_err = Z_OK;
    s->z_eof = 0;
    clearerr(s->file);
}

   windowBits is in the range 8..15, and window is a user-supplied
   window and output buffer that is 2**windowBits bytes.
 */
int ZEXPORT inflateBackInit_(
z_streamp strm,
int windowBits,
unsigned char FAR *window,
const char *version,
int stream_size)
{
    struct inflate_state FAR *state;

    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
        stream_size != (int)(sizeof(z_stream)))
        return Z_VERSION_ERROR;
    if (strm == Z_NULL || window == Z_NULL ||
        windowBits < 8 || windowBits > 15)
        return Z_STREAM_ERROR;
    strm->msg = Z_NULL;                 /* in case we return an error */
    if (strm->zalloc == (alloc_func)0) {
        strm->zalloc = zcalloc;
        strm->opaque = (voidpf)0;
    }
    if (strm->zfree == (free_func)0) strm->zfree = zcfree;
    state = (struct inflate_state FAR *)ZALLOC(strm, 1,
                                               sizeof(struct inflate_state));
    if (state == Z_NULL) return Z_MEM_ERROR;
    Tracev((stderr, "inflate: allocated\n"));
    strm->state = (struct internal_state FAR *)state;
    state->dmax = 32768U;
    state->wbits = windowBits;
    state->wsize = 1U << windowBits;
    state->window = window;
    state->write = 0;
    state->whave = 0;
    return Z_OK;
}

local void fixedtables(
struct inflate_state FAR *state)
{
#ifdef BUILDFIXED
    static int virgin = 1;
    static code *lenfix, *distfix;
    static code fixed[544];

    /* build fixed huffman tables if first call (may not be thread safe) */
    if (virgin) {
        unsigned sym, bits;
        static code *next;

        /* literal/length table */
        sym = 0;
        while (sym < 144) state->lens[sym++] = 8;
        while (sym < 256) state->lens[sym++] = 9;
        while (sym < 280) state->lens[sym++] = 7;
        while (sym < 288) state->lens[sym++] = 8;
        next = fixed;
        lenfix = next;
        bits = 9;
        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);

        /* distance table */
        sym = 0;
        while (sym < 32) state->lens[sym++] = 5;
        distfix = next;
        bits = 5;
        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);

        /* do this just once */
        virgin = 0;
    }
#else /* !BUILDFIXED */
#   include "inffixed.h"
#endif /* BUILDFIXED */
    state->lencode = lenfix;
    state->lenbits = 9;
    state->distcode = distfix;
    state->distbits = 5;
}

/* Macros for inflateBack(): */

/* Load returned state from inflate_fast() */
#define LOAD() \
    do { \
        put = strm->next_out; \
        left = strm->avail_out; \
        next = strm->next_in; \
        have = strm->avail_in; \
        hold = state->hold; \
        bits = state->bits; \
    } while (0)

/* Set state from registers for inflate_fast() */
#define RESTORE() \
    do { \
        strm->next_out = put; \
        strm->avail_out = left; \
        strm->next_in = next; \
        strm->avail_in = have; \
        state->hold = hold; \
        state->bits = bits; \
    } while (0)

/* Clear the input bit accumulator */
#define INITBITS() \
    do { \
        hold = 0; \
        bits = 0; \
    } while (0)

/* Assure that some input is available.  If input is requested, but denied,
   then return a Z_BUF_ERROR from inflateBack(). */
#define PULL() \
    do { \
        if (have == 0) { \
            have = in(in_desc, &next); \
            if (have == 0) { \
                next = Z_NULL; \
                ret = Z_BUF_ERROR; \
                goto inf_leave; \
            } \
        } \
    } while (0)

/* Get a byte of input into the bit accumulator, or return from inflateBack()
   with an error if there is no input available. */
#define PULLBYTE() \
    do { \
        PULL(); \
        have--; \
        hold += (unsigned long)(*next++) << bits; \
        bits += 8; \
    } while (0)

/* Assure that there are at least n bits in the bit accumulator.  If there is
   not enough available input to do that, then return from inflateBack() with
   an error. */
#define NEEDBITS(n) \
    do { \
        while (bits < (unsigned)(n)) \
            PULLBYTE(); \
    } while (0)

/* Return the low n bits of the bit accumulator (n < 16) */
#define BITS(n) \
    ((unsigned)hold & ((1U << (n)) - 1))

/* Remove n bits from the bit accumulator */
#define DROPBITS(n) \
    do { \
        hold >>= (n); \
        bits -= (unsigned)(n); \
    } while (0)

/* Remove zero to seven bits as needed to go to a byte boundary */
#define BYTEBITS() \
    do { \
        hold >>= bits & 7; \
        bits -= bits & 7; \
    } while (0)

/* Assure that some output space is available, by writing out the window
   if it's full.  If the write fails, return from inflateBack() with a
   Z_BUF_ERROR. */
#define ROOM() \
    do { \
        if (left == 0) { \
            put = state->window; \
            left = state->wsize; \
            state->whave = left; \
            if (out(out_desc, put, left)) { \
                ret = Z_BUF_ERROR; \
                goto inf_leave; \
            } \
        } \
    } while (0)

/*
   strm provides the memory allocation functions and window buffer on input,
   and provides information on the unused input on return.  For Z_DATA_ERROR
   returns, strm will also provide an error message.

   in() and out() are the call-back input and output functions.  When
   inflateBack() needs more input, it calls in().  When inflateBack() has
   filled the window with output, or when it completes with data in the
   window, it calls out() to write out the data.  The application must not
   change the provided input until in() is called again or inflateBack()
   returns.  The application must not change the window/output buffer until
   inflateBack() returns.

   in() and out() are called with a descriptor parameter provided in the
   inflateBack() call.  This parameter can be a structure that provides the
   information required to do the read or write, as well as accumulated
   information on the input and output such as totals and check values.

   in() should return zero on failure.  out() should return non-zero on
   failure.  If either in() or out() fails, than inflateBack() returns a
   Z_BUF_ERROR.  strm->next_in can be checked for Z_NULL to see whether it
   was in() or out() that caused in the error.  Otherwise,  inflateBack()
   returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
   error, or Z_MEM_ERROR if it could not allocate memory for the state.
   inflateBack() can also return Z_STREAM_ERROR if the input parameters
   are not correct, i.e. strm is Z_NULL or the state was not initialized.
 */
int ZEXPORT inflateBack(
z_streamp strm,
in_func in,
void FAR *in_desc,
out_func out,
void FAR *out_desc)
{
    struct inflate_state FAR *state;
    unsigned char FAR *next;    /* next input */
    unsigned char FAR *put;     /* next output */
    unsigned have, left;        /* available input and output */
    unsigned long hold;         /* bit buffer */
    unsigned bits;              /* bits in bit buffer */
    unsigned copy;              /* number of stored or match bytes to copy */
    unsigned char FAR *from;    /* where to copy match bytes from */
    code self;                  /* current decoding table entry */
    code last;                  /* parent table entry */
    unsigned len;               /* length to copy for repeats, bits to drop */
    int ret;                    /* return code */
    static const unsigned short order[19] = /* permutation of code lengths */
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};

    /* Check that the strm exists and that the state was initialized */
    if (strm == Z_NULL || strm->state == Z_NULL)
        return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;

    /* Reset the state */
    strm->msg = Z_NULL;
    state->mode = TYPE;
    state->last = 0;
    state->whave = 0;
    next = strm->next_in;
    have = next != Z_NULL ? strm->avail_in : 0;
    hold = 0;
    bits = 0;
    put = state->window;
    left = state->wsize;

    /* Inflate until end of block marked as last */
    for (;;)
        switch (state->mode) {
        case TYPE:
            /* determine and dispatch block type */
            if (state->last) {
                BYTEBITS();
                state->mode = DONE;
                break;
            }
            NEEDBITS(3);
            state->last = BITS(1);
            DROPBITS(1);
            switch (BITS(2)) {
            case 0:                             /* stored block */
                Tracev((stderr, "inflate:     stored block%s\n",
                        state->last ? " (last)" : ""));
                state->mode = STORED;
                break;
            case 1:                             /* fixed block */
                fixedtables(state);
                Tracev((stderr, "inflate:     fixed codes block%s\n",
                        state->last ? " (last)" : ""));
                state->mode = LEN;              /* decode codes */
                break;
            case 2:                             /* dynamic block */
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
                        state->last ? " (last)" : ""));
                state->mode = TABLE;
                break;
            case 3:
                strm->msg = (char *)"invalid block type";
                state->mode = BAD;
            }
            DROPBITS(2);
            break;

        case STORED:
            /* get and verify stored block length */
            BYTEBITS();                         /* go to byte boundary */
            NEEDBITS(32);
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
                strm->msg = (char *)"invalid stored block lengths";
                state->mode = BAD;
                break;
            }
            state->length = (unsigned)hold & 0xffff;
            Tracev((stderr, "inflate:       stored length %u\n",
                    state->length));
            INITBITS();

            /* copy stored block from input to output */
            while (state->length != 0) {
                copy = state->length;
                PULL();
                ROOM();
                if (copy > have) copy = have;
                if (copy > left) copy = left;
                zmemcpy(put, next, copy);
                have -= copy;
                next += copy;
                left -= copy;
                put += copy;
                state->length -= copy;
            }
            Tracev((stderr, "inflate:       stored end\n"));
            state->mode = TYPE;
            break;

        case TABLE:
            /* get dynamic table entries descriptor */
            NEEDBITS(14);
            state->nlen = BITS(5) + 257;
            DROPBITS(5);
            state->ndist = BITS(5) + 1;
            DROPBITS(5);
            state->ncode = BITS(4) + 4;
            DROPBITS(4);
#ifndef PKZIP_BUG_WORKAROUND
            if (state->nlen > 286 || state->ndist > 30) {
                strm->msg = (char *)"too many length or distance symbols";
                state->mode = BAD;
                break;
            }
#endif
            Tracev((stderr, "inflate:       table sizes ok\n"));

            /* get code length code lengths (not a typo) */
            state->have = 0;
            while (state->have < state->ncode) {
                NEEDBITS(3);
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
                DROPBITS(3);
            }
            while (state->have < 19)
                state->lens[order[state->have++]] = 0;
            state->next = state->codes;
            state->lencode = (code const FAR *)(state->next);
            state->lenbits = 7;
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
                                &(state->lenbits), state->work);
            if (ret) {
                strm->msg = (char *)"invalid code lengths set";
                state->mode = BAD;
                break;
            }
            Tracev((stderr, "inflate:       code lengths ok\n"));

            /* get length and distance code code lengths */
            state->have = 0;
            while (state->have < state->nlen + state->ndist) {
                for (;;) {
                    self = state->lencode[BITS(state->lenbits)];
                    if ((unsigned)(self.bits) <= bits) break;
                    PULLBYTE();
                }
                if (self.val < 16) {
                    NEEDBITS(self.bits);
                    DROPBITS(self.bits);
                    state->lens[state->have++] = self.val;
                }
                else {
                    if (self.val == 16) {
                        NEEDBITS(self.bits + 2);
                        DROPBITS(self.bits);
                        if (state->have == 0) {
                            strm->msg = (char *)"invalid bit length repeat";
                            state->mode = BAD;
                            break;
                        }
                        len = (unsigned)(state->lens[state->have - 1]);
                        copy = 3 + BITS(2);
                        DROPBITS(2);
                    }
                    else if (self.val == 17) {
                        NEEDBITS(self.bits + 3);
                        DROPBITS(self.bits);
                        len = 0;
                        copy = 3 + BITS(3);
                        DROPBITS(3);
                    }
                    else {
                        NEEDBITS(self.bits + 7);
                        DROPBITS(self.bits);
                        len = 0;
                        copy = 11 + BITS(7);
                        DROPBITS(7);
                    }
                    if (state->have + copy > state->nlen + state->ndist) {
                        strm->msg = (char *)"invalid bit length repeat";
                        state->mode = BAD;
                        break;
                    }
                    while (copy--)
                        state->lens[state->have++] = (unsigned short)len;
                }
            }

            /* handle error breaks in while */
            if (state->mode == BAD) break;

            /* build code tables */
            state->next = state->codes;
            state->lencode = (code const FAR *)(state->next);
            state->lenbits = 9;
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
                                &(state->lenbits), state->work);
            if (ret) {
                strm->msg = (char *)"invalid literal/lengths set";
                state->mode = BAD;
                break;
            }
            state->distcode = (code const FAR *)(state->next);
            state->distbits = 6;
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
                            &(state->next), &(state->distbits), state->work);
            if (ret) {
                strm->msg = (char *)"invalid distances set";
                state->mode = BAD;
                break;
            }
            Tracev((stderr, "inflate:       codes ok\n"));
            state->mode = LEN;

        case LEN:
            /* use inflate_fast() if we have enough input and output */
            if (have >= 6 && left >= 258) {
                RESTORE();
                if (state->whave < state->wsize)
                    state->whave = state->wsize - left;
                inflate_fast(strm, state->wsize);
                LOAD();
                break;
            }

            /* get a literal, length, or end-of-block code */
            for (;;) {
                self = state->lencode[BITS(state->lenbits)];
                if ((unsigned)(self.bits) <= bits) break;
                PULLBYTE();
            }
            if (self.op && (self.op & 0xf0) == 0) {
                last = self;
                for (;;) {
                    self = state->lencode[last.val +
                            (BITS(last.bits + last.op) >> last.bits)];
                    if ((unsigned)(last.bits + self.bits) <= bits) break;
                    PULLBYTE();
                }
                DROPBITS(last.bits);
            }
            DROPBITS(self.bits);
            state->length = (unsigned)self.val;

            /* process literal */
            if (self.op == 0) {
                Tracevv((stderr, self.val >= 0x20 && self.val < 0x7f ?
                        "inflate:         literal '%c'\n" :
                        "inflate:         literal 0x%02x\n", self.val));
                ROOM();
                *put++ = (unsigned char)(state->length);
                left--;
                state->mode = LEN;
                break;
            }

            /* process end of block */
            if (self.op & 32) {
                Tracevv((stderr, "inflate:         end of block\n"));
                state->mode = TYPE;
                break;
            }

            /* invalid code */
            if (self.op & 64) {
                strm->msg = (char *)"invalid literal/length code";
                state->mode = BAD;
                break;
            }

            /* length code -- get extra bits, if any */
            state->extra = (unsigned)(self.op) & 15;
            if (state->extra != 0) {
                NEEDBITS(state->extra);
                state->length += BITS(state->extra);
                DROPBITS(state->extra);
            }
            Tracevv((stderr, "inflate:         length %u\n", state->length));

            /* get distance code */
            for (;;) {
                self = state->distcode[BITS(state->distbits)];
                if ((unsigned)(self.bits) <= bits) break;
                PULLBYTE();
            }
            if ((self.op & 0xf0) == 0) {
                last = self;
                for (;;) {
                    self = state->distcode[last.val +
                            (BITS(last.bits + last.op) >> last.bits)];
                    if ((unsigned)(last.bits + self.bits) <= bits) break;
                    PULLBYTE();
                }
                DROPBITS(last.bits);
            }
            DROPBITS(self.bits);
            if (self.op & 64) {
                strm->msg = (char *)"invalid distance code";
                state->mode = BAD;
                break;
            }
            state->offset = (unsigned)self.val;

            /* get distance extra bits, if any */
            state->extra = (unsigned)(self.op) & 15;
            if (state->extra != 0) {
                NEEDBITS(state->extra);
                state->offset += BITS(state->extra);
                DROPBITS(state->extra);
            }
            if (state->offset > state->wsize - (state->whave < state->wsize ?
                                                left : 0)) {
                strm->msg = (char *)"invalid distance too far back";
                state->mode = BAD;
                break;
            }
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));

            /* copy match from window to output */
            do {
                ROOM();
                copy = state->wsize - state->offset;
                if (copy < left) {
                    from = put + copy;
                    copy = left - copy;
                }
                else {
                    from = put - state->offset;
                    copy = left;
                }
                if (copy > state->length) copy = state->length;
                state->length -= copy;
                left -= copy;
                do {
                    *put++ = *from++;
                } while (--copy);
            } while (state->length != 0);
            break;

        case DONE:
            /* inflate stream terminated properly -- write leftover output */
            ret = Z_STREAM_END;
            if (left < state->wsize) {
                if (out(out_desc, state->window, state->wsize - left))
                    ret = Z_BUF_ERROR;
            }
            goto inf_leave;

        case BAD:
            ret = Z_DATA_ERROR;
            goto inf_leave;

        default:                /* can't happen, but makes compilers happy */
            ret = Z_STREAM_ERROR;
            goto inf_leave;
        }

    /* Return unused input */
  inf_leave:
    strm->next_in = next;
    strm->avail_in = have;
    return ret;
}

int ZEXPORT inflateBackEnd(
z_streamp strm)
{
    if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
        return Z_STREAM_ERROR;
    ZFREE(strm, strm->state);
    strm->state = Z_NULL;
    Tracev((stderr, "inflate: end\n"));
    return Z_OK;
}

    - The maximum bytes that a single length/distance pair can output is 258
      bytes, which is the maximum length that can be coded.  inflate_fast()
      requires strm->avail_out >= 258 for each loop to avoid checking for
      output space.
 */
void inflate_fast(
z_streamp strm,
unsigned start)         /* inflate()'s starting value for strm->avail_out */
{
    struct inflate_state FAR *state;
    unsigned char FAR *in;      /* local strm->next_in */
    unsigned char FAR *last;    /* while in < last, enough input available */
    unsigned char FAR *out;     /* local strm->next_out */
    unsigned char FAR *beg;     /* inflate()'s initial strm->next_out */
    unsigned char FAR *end;     /* while out < end, enough space available */
#ifdef INFLATE_STRICT
    unsigned dmax;              /* maximum distance from zlib header */
#endif
    unsigned wsize;             /* window size or zero if not using window */
    unsigned whave;             /* valid bytes in the window */
    unsigned write;             /* window write index */
    unsigned char FAR *window;  /* allocated sliding window, if wsize != 0 */
    unsigned long hold;         /* local strm->hold */
    unsigned bits;              /* local strm->bits */
    code const FAR *lcode;      /* local strm->lencode */
    code const FAR *dcode;      /* local strm->distcode */
    unsigned lmask;             /* mask for first level of length codes */
    unsigned dmask;             /* mask for first level of distance codes */
    code self;                  /* retrieved table entry */
    unsigned op;                /* code bits, operation, extra bits, or */
                                /*  window position, window bytes to copy */
    unsigned len;               /* match length, unused bytes */
    unsigned dist;              /* match distance */
    unsigned char FAR *from;    /* where to copy match from */

    /* copy state to local variables */
    state = (struct inflate_state FAR *)strm->state;
    in = strm->next_in - OFF;
    last = in + (strm->avail_in - 5);
    out = strm->next_out - OFF;
    beg = out - (start - strm->avail_out);
    end = out + (strm->avail_out - 257);
#ifdef INFLATE_STRICT
    dmax = state->dmax;
#endif
    wsize = state->wsize;
    whave = state->whave;
    write = state->write;
    window = state->window;
    hold = state->hold;
    bits = state->bits;
    lcode = state->lencode;
    dcode = state->distcode;
    lmask = (1U << state->lenbits) - 1;
    dmask = (1U << state->distbits) - 1;

    /* decode literals and length/distances until end-of-block or not enough
       input data or output space */
    do {
        if (bits < 15) {
            hold += (unsigned long)(PUP(in)) << bits;
            bits += 8;
            hold += (unsigned long)(PUP(in)) << bits;
            bits += 8;
        }
        self = lcode[hold & lmask];
      dolen:
        op = (unsigned)(self.bits);
        hold >>= op;
        bits -= op;
        op = (unsigned)(self.op);
        if (op == 0) {                          /* literal */
            Tracevv((stderr, self.val >= 0x20 && self.val < 0x7f ?
                    "inflate:         literal '%c'\n" :
                    "inflate:         literal 0x%02x\n", self.val));
            PUP(out) = (unsigned char)(self.val);
        }
        else if (op & 16) {                     /* length base */
            len = (unsigned)(self.val);
            op &= 15;                           /* number of extra bits */
            if (op) {
                if (bits < op) {
                    hold += (unsigned long)(PUP(in)) << bits;
                    bits += 8;
                }
                len += (unsigned)hold & ((1U << op) - 1);
                hold >>= op;
                bits -= op;
            }
            Tracevv((stderr, "inflate:         length %u\n", len));
            if (bits < 15) {
                hold += (unsigned long)(PUP(in)) << bits;
                bits += 8;
                hold += (unsigned long)(PUP(in)) << bits;
                bits += 8;
            }
            self = dcode[hold & dmask];
          dodist:
            op = (unsigned)(self.bits);
            hold >>= op;
            bits -= op;
            op = (unsigned)(self.op);
            if (op & 16) {                      /* distance base */
                dist = (unsigned)(self.val);
                op &= 15;                       /* number of extra bits */
                if (bits < op) {
                    hold += (unsigned long)(PUP(in)) << bits;
                    bits += 8;
                    if (bits < op) {
                        hold += (unsigned long)(PUP(in)) << bits;
                        bits += 8;
                    }
                }
                dist += (unsigned)hold & ((1U << op) - 1);
#ifdef INFLATE_STRICT
                if (dist > dmax) {
                    strm->msg = (char *)"invalid distance too far back";
                    state->mode = BAD;
                    break;
                }
#endif
                hold >>= op;
                bits -= op;
                Tracevv((stderr, "inflate:         distance %u\n", dist));
                op = (unsigned)(out - beg);     /* max distance in output */
                if (dist > op) {                /* see if copy from window */
                    op = dist - op;             /* distance back in window */
                    if (op > whave) {
                        strm->msg = (char *)"invalid distance too far back";
                        state->mode = BAD;
                        break;
                    }
                    from = window - OFF;
                    if (write == 0) {           /* very common case */
                        from += wsize - op;
                        if (op < len) {         /* some from window */
                            len -= op;
                            do {
                                PUP(out) = PUP(from);
                            } while (--op);
                            from = out - dist;  /* rest from output */
                        }
                    }
                    else if (write < op) {      /* wrap around window */
                        from += wsize + write - op;
                        op -= write;
                        if (op < len) {         /* some from end of window */
                            len -= op;
                            do {
                                PUP(out) = PUP(from);
                            } while (--op);
                            from = window - OFF;
                            if (write < len) {  /* some from start of window */
                                op = write;
                                len -= op;
                                do {
                                    PUP(out) = PUP(from);
                                } while (--op);
                                from = out - dist;      /* rest from output */
                            }
                        }
                    }
                    else {                      /* contiguous in window */
                        from += write - op;
                        if (op < len) {         /* some from window */
                            len -= op;
                            do {
                                PUP(out) = PUP(from);
                            } while (--op);
                            from = out - dist;  /* rest from output */
                        }
                    }
                    while (len > 2) {
                        PUP(out) = PUP(from);
                        PUP(out) = PUP(from);
                        PUP(out) = PUP(from);
                        len -= 3;
                    }
                    if (len) {
                        PUP(out) = PUP(from);
                        if (len > 1)
                            PUP(out) = PUP(from);
                    }
                }
                else {
                    from = out - dist;          /* copy direct from output */
                    do {                        /* minimum length is three */
                        PUP(out) = PUP(from);
                        PUP(out) = PUP(from);
                        PUP(out) = PUP(from);
                        len -= 3;
                    } while (len > 2);
                    if (len) {
                        PUP(out) = PUP(from);
                        if (len > 1)
                            PUP(out) = PUP(from);
                    }
                }
            }
            else if ((op & 64) == 0) {          /* 2nd level distance code */
                self = dcode[self.val + (hold & ((1U << op) - 1))];
                goto dodist;
            }
            else {
                strm->msg = (char *)"invalid distance code";
                state->mode = BAD;
                break;
            }
        }
        else if ((op & 64) == 0) {              /* 2nd level length code */
            self = lcode[self.val + (hold & ((1U << op) - 1))];
            goto dolen;
        }
        else if (op & 32) {                     /* end-of-block */
            Tracevv((stderr, "inflate:         end of block\n"));
            state->mode = TYPE;
            break;
        }
        else {
            strm->msg = (char *)"invalid literal/length code";
            state->mode = BAD;
            break;
        }
    } while (in < last && out < end);

    /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
    len = bits >> 3;
    in -= len;
    bits -= len << 3;
    hold &= (1U << bits) - 1;

    /* update state and return */
    strm->next_in = in + OFF;
    strm->next_out = out + OFF;
    strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
    strm->avail_out = (unsigned)(out < end ?
                                 257 + (end - out) : 257 - (out - end));
    state->hold = hold;
    state->bits = bits;
    return;
}

int ZEXPORT inflateReset(
z_streamp strm)
{
    struct inflate_state FAR *state;

    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    strm->total_in = strm->total_out = state->total = 0;
    strm->msg = Z_NULL;
    strm->adler = 1;        /* to support ill-conceived Java test suite */
    state->mode = HEAD;
    state->last = 0;
    state->havedict = 0;
    state->dmax = 32768U;
    state->head = Z_NULL;
    state->wsize = 0;
    state->whave = 0;
    state->write = 0;
    state->hold = 0;
    state->bits = 0;
    state->lencode = state->distcode = state->next = state->codes;
    Tracev((stderr, "inflate: reset\n"));
    return Z_OK;
}

int ZEXPORT inflatePrime(
z_streamp strm,
int bits,
int value)
{
    struct inflate_state FAR *state;

    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
    value &= (1L << bits) - 1;
    state->hold += value << state->bits;
    state->bits += bits;
    return Z_OK;
}

int ZEXPORT inflateInit2_(
z_streamp strm,
int windowBits,
const char *version,
int stream_size)
{
    struct inflate_state FAR *state;

    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
        stream_size != (int)(sizeof(z_stream)))
        return Z_VERSION_ERROR;
    if (strm == Z_NULL) return Z_STREAM_ERROR;
    strm->msg = Z_NULL;                 /* in case we return an error */
    if (strm->zalloc == (alloc_func)0) {
        strm->zalloc = zcalloc;
        strm->opaque = (voidpf)0;
    }
    if (strm->zfree == (free_func)0) strm->zfree = zcfree;
    state = (struct inflate_state FAR *)
            ZALLOC(strm, 1, sizeof(struct inflate_state));
    if (state == Z_NULL) return Z_MEM_ERROR;
    Tracev((stderr, "inflate: allocated\n"));
    strm->state = (struct internal_state FAR *)state;
    if (windowBits < 0) {
        state->wrap = 0;
        windowBits = -windowBits;
    }
    else {
        state->wrap = (windowBits >> 4) + 1;
#ifdef GUNZIP
        if (windowBits < 48) windowBits &= 15;
#endif
    }
    if (windowBits < 8 || windowBits > 15) {
        ZFREE(strm, state);
        strm->state = Z_NULL;
        return Z_STREAM_ERROR;
    }
    state->wbits = (unsigned)windowBits;
    state->window = Z_NULL;
    return inflateReset(strm);
}

int ZEXPORT inflateInit_(
z_streamp strm,
const char *version,
int stream_size)
{
    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
}

local void fixedtables(
struct inflate_state FAR *state)
{
#ifdef BUILDFIXED
    static int virgin = 1;
    static code *lenfix, *distfix;
    static code fixed[544];

    /* build fixed huffman tables if first call (may not be thread safe) */
    if (virgin) {
        unsigned sym, bits;
        static code *next;

        /* literal/length table */
        sym = 0;
        while (sym < 144) state->lens[sym++] = 8;
        while (sym < 256) state->lens[sym++] = 9;
        while (sym < 280) state->lens[sym++] = 7;
        while (sym < 288) state->lens[sym++] = 8;
        next = fixed;
        lenfix = next;
        bits = 9;
        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);

        /* distance table */
        sym = 0;
        while (sym < 32) state->lens[sym++] = 5;
        distfix = next;
        bits = 5;
        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);

        /* do this just once */
        virgin = 0;
    }
#else /* !BUILDFIXED */
#   include "inffixed.h"
#endif /* BUILDFIXED */
    state->lencode = lenfix;
    state->lenbits = 9;
    state->distcode = distfix;
    state->distbits = 5;
}

#ifdef MAKEFIXED
#include 

/*
   Write out the inffixed.h that is #include'd above.  Defining MAKEFIXED also
   defines BUILDFIXED, so the tables are built on the fly.  makefixed() writes
   those tables to stdout, which would be piped to inffixed.h.  A small program
   can simply call makefixed to do this:

    void makefixed(void);

    int main(void)
    {
        makefixed();
        return 0;
    }

   Then that can be linked with zlib built with MAKEFIXED defined and run:

    a.out > inffixed.h
 */
void makefixed()
{
    unsigned low, size;
    struct inflate_state state;

    fixedtables(&state);
    puts("    /* inffixed.h -- table for decoding fixed codes");
    puts("     * Generated automatically by makefixed().");
    puts("     */");
    puts("");
    puts("    /* WARNING: this file should *not* be used by applications.");
    puts("       It is part of the implementation of this library and is");
    puts("       subject to change. Applications should only use zlib.h.");
    puts("     */");
    puts("");
    size = 1U << 9;
    printf("    static const code lenfix[%u] = {", size);
    low = 0;
    for (;;) {
        if ((low % 7) == 0) printf("\n        ");
        printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits,
               state.lencode[low].val);
        if (++low == size) break;
        putchar(',');
    }
    puts("\n    };");
    size = 1U << 5;
    printf("\n    static const code distfix[%u] = {", size);
    low = 0;
    for (;;) {
        if ((low % 6) == 0) printf("\n        ");
        printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
               state.distcode[low].val);
        if (++low == size) break;
        putchar(',');
    }
    puts("\n    };");
}
#endif /* MAKEFIXED */

/*
   Update the window with the last wsize (normally 32K) bytes written before
   returning.  If window does not exist yet, create it.  This is only called
   when a window is already in use, or when output has been written during this
   inflate call, but the end of the deflate stream has not been reached yet.
   It is also called to create a window for dictionary data when a dictionary
   is loaded.

   Providing output buffers larger than 32K to inflate() should provide a speed
   advantage, since only the last 32K of output is copied to the sliding window
   upon return from inflate(), and since all distances after the first 32K of
   output will fall in the output data, making match copies simpler and faster.
   The advantage may be dependent on the size of the processor's data caches.
 */
local int updatewindow(
z_streamp strm,
unsigned out)
{
    struct inflate_state FAR *state;
    unsigned copy, dist;

    state = (struct inflate_state FAR *)strm->state;

    /* if it hasn't been done already, allocate space for the window */
    if (state->window == Z_NULL) {
        state->window = (unsigned char FAR *)
                        ZALLOC(strm, 1U << state->wbits,
                               sizeof(unsigned char));
        if (state->window == Z_NULL) return 1;
    }

    /* if window not in use yet, initialize */
    if (state->wsize == 0) {
        state->wsize = 1U << state->wbits;
        state->write = 0;
        state->whave = 0;
    }

    /* copy state->wsize or less output bytes into the circular window */
    copy = out - strm->avail_out;
    if (copy >= state->wsize) {
        zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
        state->write = 0;
        state->whave = state->wsize;
    }
    else {
        dist = state->wsize - state->write;
        if (dist > copy) dist = copy;
        zmemcpy(state->window + state->write, strm->next_out - copy, dist);
        copy -= dist;
        if (copy) {
            zmemcpy(state->window, strm->next_out - copy, copy);
            state->write = copy;
            state->whave = state->wsize;
        }
        else {
            state->write += dist;
            if (state->write == state->wsize) state->write = 0;
            if (state->whave < state->wsize) state->whave += dist;
        }
    }
    return 0;
}

/* Macros for inflate(): */

/* check function to use adler32() for zlib or crc32() for gzip */
#ifdef GUNZIP
#  define UPDATE(check, buf, len) \
    (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
#else
#  define UPDATE(check, buf, len) adler32(check, buf, len)
#endif

/* check macros for header crc */
#ifdef GUNZIP
#  define CRC2(check, word) \
    do { \
        hbuf[0] = (unsigned char)(word); \
        hbuf[1] = (unsigned char)((word) >> 8); \
        check = crc32(check, hbuf, 2); \
    } while (0)

#  define CRC4(check, word) \
    do { \
        hbuf[0] = (unsigned char)(word); \
        hbuf[1] = (unsigned char)((word) >> 8); \
        hbuf[2] = (unsigned char)((word) >> 16); \
        hbuf[3] = (unsigned char)((word) >> 24); \
        check = crc32(check, hbuf, 4); \
    } while (0)
#endif

/* Load registers with state in inflate() for speed */
#define LOAD() \
    do { \
        put = strm->next_out; \
        left = strm->avail_out; \
        next = strm->next_in; \
        have = strm->avail_in; \
        hold = state->hold; \
        bits = state->bits; \
    } while (0)

/* Restore state from registers in inflate() */
#define RESTORE() \
    do { \
        strm->next_out = put; \
        strm->avail_out = left; \
        strm->next_in = next; \
        strm->avail_in = have; \
        state->hold = hold; \
        state->bits = bits; \
    } while (0)

/* Clear the input bit accumulator */
#define INITBITS() \
    do { \
        hold = 0; \
        bits = 0; \
    } while (0)

/* Get a byte of input into the bit accumulator, or return from inflate()
   if there is no input available. */
#define PULLBYTE() \
    do { \
        if (have == 0) goto inf_leave; \
        have--; \
        hold += (unsigned long)(*next++) << bits; \
        bits += 8; \
    } while (0)

/* Assure that there are at least n bits in the bit accumulator.  If there is
   not enough available input to do that, then return from inflate(). */
#define NEEDBITS(n) \
    do { \
        while (bits < (unsigned)(n)) \
            PULLBYTE(); \
    } while (0)

/* Return the low n bits of the bit accumulator (n < 16) */
#define BITS(n) \
    ((unsigned)hold & ((1U << (n)) - 1))

/* Remove n bits from the bit accumulator */
#define DROPBITS(n) \
    do { \
        hold >>= (n); \
        bits -= (unsigned)(n); \
    } while (0)

/* Remove zero to seven bits as needed to go to a byte boundary */
#define BYTEBITS() \
    do { \
        hold >>= bits & 7; \
        bits -= bits & 7; \
    } while (0)

/* Reverse the bytes in a 32-bit value */
#define REVERSE(q) \
    ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
     (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))

int ZEXPORT inflate(
z_streamp strm,
int flush)
{
    struct inflate_state FAR *state;
    unsigned char FAR *next;    /* next input */
    unsigned char FAR *put;     /* next output */
    unsigned have, left;        /* available input and output */
    unsigned long hold;         /* bit buffer */
    unsigned bits;              /* bits in bit buffer */
    unsigned in, out;           /* save starting available input and output */
    unsigned copy;              /* number of stored or match bytes to copy */
    unsigned char FAR *from;    /* where to copy match bytes from */
    code self;                  /* current decoding table entry */
    code last;                  /* parent table entry */
    unsigned len;               /* length to copy for repeats, bits to drop */
    int ret;                    /* return code */
#ifdef GUNZIP
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
#endif
    static const unsigned short order[19] = /* permutation of code lengths */
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};

    if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
        (strm->next_in == Z_NULL && strm->avail_in != 0))
        return Z_STREAM_ERROR;

    state = (struct inflate_state FAR *)strm->state;
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
    LOAD();
    in = have;
    out = left;
    ret = Z_OK;
    for (;;)
        switch (state->mode) {
        case HEAD:
            if (state->wrap == 0) {
                state->mode = TYPEDO;
                break;
            }
            NEEDBITS(16);
#ifdef GUNZIP
            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
                state->check = crc32(0L, Z_NULL, 0);
                CRC2(state->check, hold);
                INITBITS();
                state->mode = FLAGS;
                break;
            }
            state->flags = 0;           /* expect zlib header */
            if (state->head != Z_NULL)
                state->head->done = -1;
            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
#else
            if (
#endif
                ((BITS(8) << 8) + (hold >> 8)) % 31) {
                strm->msg = (char *)"incorrect header check";
                state->mode = BAD;
                break;
            }
            if (BITS(4) != Z_DEFLATED) {
                strm->msg = (char *)"unknown compression method";
                state->mode = BAD;
                break;
            }
            DROPBITS(4);
            len = BITS(4) + 8;
            if (len > state->wbits) {
                strm->msg = (char *)"invalid window size";
                state->mode = BAD;
                break;
            }
            state->dmax = 1U << len;
            Tracev((stderr, "inflate:   zlib header ok\n"));
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
            state->mode = hold & 0x200 ? DICTID : TYPE;
            INITBITS();
            break;
#ifdef GUNZIP
        case FLAGS:
            NEEDBITS(16);
            state->flags = (int)(hold);
            if ((state->flags & 0xff) != Z_DEFLATED) {
                strm->msg = (char *)"unknown compression method";
                state->mode = BAD;
                break;
            }
            if (state->flags & 0xe000) {
                strm->msg = (char *)"unknown header flags set";
                state->mode = BAD;
                break;
            }
            if (state->head != Z_NULL)
                state->head->text = (int)((hold >> 8) & 1);
            if (state->flags & 0x0200) CRC2(state->check, hold);
            INITBITS();
            state->mode = TIME;
        case TIME:
            NEEDBITS(32);
            if (state->head != Z_NULL)
                state->head->time = hold;
            if (state->flags & 0x0200) CRC4(state->check, hold);
            INITBITS();
            state->mode = OS;
        case OS:
            NEEDBITS(16);
            if (state->head != Z_NULL) {
                state->head->xflags = (int)(hold & 0xff);
                state->head->os = (int)(hold >> 8);
            }
            if (state->flags & 0x0200) CRC2(state->check, hold);
            INITBITS();
            state->mode = EXLEN;
        case EXLEN:
            if (state->flags & 0x0400) {
                NEEDBITS(16);
                state->length = (unsigned)(hold);
                if (state->head != Z_NULL)
                    state->head->extra_len = (unsigned)hold;
                if (state->flags & 0x0200) CRC2(state->check, hold);
                INITBITS();
            }
            else if (state->head != Z_NULL)
                state->head->extra = Z_NULL;
            state->mode = EXTRA;
        case EXTRA:
            if (state->flags & 0x0400) {
                copy = state->length;
                if (copy > have) copy = have;
                if (copy) {
                    if (state->head != Z_NULL &&
                        state->head->extra != Z_NULL) {
                        len = state->head->extra_len - state->length;
                        zmemcpy(state->head->extra + len, next,
                                len + copy > state->head->extra_max ?
                                state->head->extra_max - len : copy);
                    }
                    if (state->flags & 0x0200)
                        state->check = crc32(state->check, next, copy);
                    have -= copy;
                    next += copy;
                    state->length -= copy;
                }
                if (state->length) goto inf_leave;
            }
            state->length = 0;
            state->mode = NAME;
        case NAME:
            if (state->flags & 0x0800) {
                if (have == 0) goto inf_leave;
                copy = 0;
                do {
                    len = (unsigned)(next[copy++]);
                    if (state->head != Z_NULL &&
                            state->head->name != Z_NULL &&
                            state->length < state->head->name_max)
                        state->head->name[state->length++] = len;
                } while (len && copy < have);
                if (state->flags & 0x0200)
                    state->check = crc32(state->check, next, copy);
                have -= copy;
                next += copy;
                if (len) goto inf_leave;
            }
            else if (state->head != Z_NULL)
                state->head->name = Z_NULL;
            state->length = 0;
            state->mode = COMMENT;
        case COMMENT:
            if (state->flags & 0x1000) {
                if (have == 0) goto inf_leave;
                copy = 0;
                do {
                    len = (unsigned)(next[copy++]);
                    if (state->head != Z_NULL &&
                            state->head->comment != Z_NULL &&
                            state->length < state->head->comm_max)
                        state->head->comment[state->length++] = len;
                } while (len && copy < have);
                if (state->flags & 0x0200)
                    state->check = crc32(state->check, next, copy);
                have -= copy;
                next += copy;
                if (len) goto inf_leave;
            }
            else if (state->head != Z_NULL)
                state->head->comment = Z_NULL;
            state->mode = HCRC;
        case HCRC:
            if (state->flags & 0x0200) {
                NEEDBITS(16);
                if (hold != (state->check & 0xffff)) {
                    strm->msg = (char *)"header crc mismatch";
                    state->mode = BAD;
                    break;
                }
                INITBITS();
            }
            if (state->head != Z_NULL) {
                state->head->hcrc = (int)((state->flags >> 9) & 1);
                state->head->done = 1;
            }
            strm->adler = state->check = crc32(0L, Z_NULL, 0);
            state->mode = TYPE;
            break;
#endif
        case DICTID:
            NEEDBITS(32);
            strm->adler = state->check = REVERSE(hold);
            INITBITS();
            state->mode = DICT;
        case DICT:
            if (state->havedict == 0) {
                RESTORE();
                return Z_NEED_DICT;
            }
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
            state->mode = TYPE;
        case TYPE:
            if (flush == Z_BLOCK) goto inf_leave;
        case TYPEDO:
            if (state->last) {
                BYTEBITS();
                state->mode = CHECK;
                break;
            }
            NEEDBITS(3);
            state->last = BITS(1);
            DROPBITS(1);
            switch (BITS(2)) {
            case 0:                             /* stored block */
                Tracev((stderr, "inflate:     stored block%s\n",
                        state->last ? " (last)" : ""));
                state->mode = STORED;
                break;
            case 1:                             /* fixed block */
                fixedtables(state);
                Tracev((stderr, "inflate:     fixed codes block%s\n",
                        state->last ? " (last)" : ""));
                state->mode = LEN;              /* decode codes */
                break;
            case 2:                             /* dynamic block */
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
                        state->last ? " (last)" : ""));
                state->mode = TABLE;
                break;
            case 3:
                strm->msg = (char *)"invalid block type";
                state->mode = BAD;
            }
            DROPBITS(2);
            break;
        case STORED:
            BYTEBITS();                         /* go to byte boundary */
            NEEDBITS(32);
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
                strm->msg = (char *)"invalid stored block lengths";
                state->mode = BAD;
                break;
            }
            state->length = (unsigned)hold & 0xffff;
            Tracev((stderr, "inflate:       stored length %u\n",
                    state->length));
            INITBITS();
            state->mode = COPY;
        case COPY:
            copy = state->length;
            if (copy) {
                if (copy > have) copy = have;
                if (copy > left) copy = left;
                if (copy == 0) goto inf_leave;
                zmemcpy(put, next, copy);
                have -= copy;
                next += copy;
                left -= copy;
                put += copy;
                state->length -= copy;
                break;
            }
            Tracev((stderr, "inflate:       stored end\n"));
            state->mode = TYPE;
            break;
        case TABLE:
            NEEDBITS(14);
            state->nlen = BITS(5) + 257;
            DROPBITS(5);
            state->ndist = BITS(5) + 1;
            DROPBITS(5);
            state->ncode = BITS(4) + 4;
            DROPBITS(4);
#ifndef PKZIP_BUG_WORKAROUND
            if (state->nlen > 286 || state->ndist > 30) {
                strm->msg = (char *)"too many length or distance symbols";
                state->mode = BAD;
                break;
            }
#endif
            Tracev((stderr, "inflate:       table sizes ok\n"));
            state->have = 0;
            state->mode = LENLENS;
        case LENLENS:
            while (state->have < state->ncode) {
                NEEDBITS(3);
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
                DROPBITS(3);
            }
            while (state->have < 19)
                state->lens[order[state->have++]] = 0;
            state->next = state->codes;
            state->lencode = (code const FAR *)(state->next);
            state->lenbits = 7;
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
                                &(state->lenbits), state->work);
            if (ret) {
                strm->msg = (char *)"invalid code lengths set";
                state->mode = BAD;
                break;
            }
            Tracev((stderr, "inflate:       code lengths ok\n"));
            state->have = 0;
            state->mode = CODELENS;
        case CODELENS:
            while (state->have < state->nlen + state->ndist) {
                for (;;) {
                    self = state->lencode[BITS(state->lenbits)];
                    if ((unsigned)(self.bits) <= bits) break;
                    PULLBYTE();
                }
                if (self.val < 16) {
                    NEEDBITS(self.bits);
                    DROPBITS(self.bits);
                    state->lens[state->have++] = self.val;
                }
                else {
                    if (self.val == 16) {
                        NEEDBITS(self.bits + 2);
                        DROPBITS(self.bits);
                        if (state->have == 0) {
                            strm->msg = (char *)"invalid bit length repeat";
                            state->mode = BAD;
                            break;
                        }
                        len = state->lens[state->have - 1];
                        copy = 3 + BITS(2);
                        DROPBITS(2);
                    }
                    else if (self.val == 17) {
                        NEEDBITS(self.bits + 3);
                        DROPBITS(self.bits);
                        len = 0;
                        copy = 3 + BITS(3);
                        DROPBITS(3);
                    }
                    else {
                        NEEDBITS(self.bits + 7);
                        DROPBITS(self.bits);
                        len = 0;
                        copy = 11 + BITS(7);
                        DROPBITS(7);
                    }
                    if (state->have + copy > state->nlen + state->ndist) {
                        strm->msg = (char *)"invalid bit length repeat";
                        state->mode = BAD;
                        break;
                    }
                    while (copy--)
                        state->lens[state->have++] = (unsigned short)len;
                }
            }

            /* handle error breaks in while */
            if (state->mode == BAD) break;

            /* build code tables */
            state->next = state->codes;
            state->lencode = (code const FAR *)(state->next);
            state->lenbits = 9;
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
                                &(state->lenbits), state->work);
            if (ret) {
                strm->msg = (char *)"invalid literal/lengths set";
                state->mode = BAD;
                break;
            }
            state->distcode = (code const FAR *)(state->next);
            state->distbits = 6;
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
                            &(state->next), &(state->distbits), state->work);
            if (ret) {
                strm->msg = (char *)"invalid distances set";
                state->mode = BAD;
                break;
            }
            Tracev((stderr, "inflate:       codes ok\n"));
            state->mode = LEN;
        case LEN:
            if (have >= 6 && left >= 258) {
                RESTORE();
                inflate_fast(strm, out);
                LOAD();
                break;
            }
            for (;;) {
                self = state->lencode[BITS(state->lenbits)];
                if ((unsigned)(self.bits) <= bits) break;
                PULLBYTE();
            }
            if (self.op && (self.op & 0xf0) == 0) {
                last = self;
                for (;;) {
                    self = state->lencode[last.val +
                            (BITS(last.bits + last.op) >> last.bits)];
                    if ((unsigned)(last.bits + self.bits) <= bits) break;
                    PULLBYTE();
                }
                DROPBITS(last.bits);
            }
            DROPBITS(self.bits);
            state->length = (unsigned)self.val;
            if ((int)(self.op) == 0) {
                Tracevv((stderr, self.val >= 0x20 && self.val < 0x7f ?
                        "inflate:         literal '%c'\n" :
                        "inflate:         literal 0x%02x\n", self.val));
                state->mode = LIT;
                break;
            }
            if (self.op & 32) {
                Tracevv((stderr, "inflate:         end of block\n"));
                state->mode = TYPE;
                break;
            }
            if (self.op & 64) {
                strm->msg = (char *)"invalid literal/length code";
                state->mode = BAD;
                break;
            }
            state->extra = (unsigned)(self.op) & 15;
            state->mode = LENEXT;
        case LENEXT:
            if (state->extra) {
                NEEDBITS(state->extra);
                state->length += BITS(state->extra);
                DROPBITS(state->extra);
            }
            Tracevv((stderr, "inflate:         length %u\n", state->length));
            state->mode = DIST;
        case DIST:
            for (;;) {
                self = state->distcode[BITS(state->distbits)];
                if ((unsigned)(self.bits) <= bits) break;
                PULLBYTE();
            }
            if ((self.op & 0xf0) == 0) {
                last = self;
                for (;;) {
                    self = state->distcode[last.val +
                            (BITS(last.bits + last.op) >> last.bits)];
                    if ((unsigned)(last.bits + self.bits) <= bits) break;
                    PULLBYTE();
                }
                DROPBITS(last.bits);
            }
            DROPBITS(self.bits);
            if (self.op & 64) {
                strm->msg = (char *)"invalid distance code";
                state->mode = BAD;
                break;
            }
            state->offset = (unsigned)self.val;
            state->extra = (unsigned)(self.op) & 15;
            state->mode = DISTEXT;
        case DISTEXT:
            if (state->extra) {
                NEEDBITS(state->extra);
                state->offset += BITS(state->extra);
                DROPBITS(state->extra);
            }
#ifdef INFLATE_STRICT
            if (state->offset > state->dmax) {
                strm->msg = (char *)"invalid distance too far back";
                state->mode = BAD;
                break;
            }
#endif
            if (state->offset > state->whave + out - left) {
                strm->msg = (char *)"invalid distance too far back";
                state->mode = BAD;
                break;
            }
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
            state->mode = MATCH;
        case MATCH:
            if (left == 0) goto inf_leave;
            copy = out - left;
            if (state->offset > copy) {         /* copy from window */
                copy = state->offset - copy;
                if (copy > state->write) {
                    copy -= state->write;
                    from = state->window + (state->wsize - copy);
                }
                else
                    from = state->window + (state->write - copy);
                if (copy > state->length) copy = state->length;
            }
            else {                              /* copy from output */
                from = put - state->offset;
                copy = state->length;
            }
            if (copy > left) copy = left;
            left -= copy;
            state->length -= copy;
            do {
                *put++ = *from++;
            } while (--copy);
            if (state->length == 0) state->mode = LEN;
            break;
        case LIT:
            if (left == 0) goto inf_leave;
            *put++ = (unsigned char)(state->length);
            left--;
            state->mode = LEN;
            break;
        case CHECK:
            if (state->wrap) {
                NEEDBITS(32);
                out -= left;
                strm->total_out += out;
                state->total += out;
                if (out)
                    strm->adler = state->check =
                        UPDATE(state->check, put - out, out);
                out = left;
                if ((
#ifdef GUNZIP
                     state->flags ? hold :
#endif
                     REVERSE(hold)) != state->check) {
                    strm->msg = (char *)"incorrect data check";
                    state->mode = BAD;
                    break;
                }
                INITBITS();
                Tracev((stderr, "inflate:   check matches trailer\n"));
            }
#ifdef GUNZIP
            state->mode = LENGTH;
        case LENGTH:
            if (state->wrap && state->flags) {
                NEEDBITS(32);
                if (hold != (state->total & 0xffffffffUL)) {
                    strm->msg = (char *)"incorrect length check";
                    state->mode = BAD;
                    break;
                }
                INITBITS();
                Tracev((stderr, "inflate:   length matches trailer\n"));
            }
#endif
            state->mode = DONE;
        case DONE:
            ret = Z_STREAM_END;
            goto inf_leave;
        case BAD:
            ret = Z_DATA_ERROR;
            goto inf_leave;
        case MEM:
            return Z_MEM_ERROR;
        case SYNC:
        default:
            return Z_STREAM_ERROR;
        }

    /*
       Return from inflate(), updating the total counts and the check value.
       If there was no progress during the inflate() call, return a buffer
       error.  Call updatewindow() to create and/or update the window state.
       Note: a memory error from inflate() is non-recoverable.
     */
  inf_leave:
    RESTORE();
    if (state->wsize || (state->mode < CHECK && out != strm->avail_out))
        if (updatewindow(strm, out)) {
            state->mode = MEM;
            return Z_MEM_ERROR;
        }
    in -= strm->avail_in;
    out -= strm->avail_out;
    strm->total_in += in;
    strm->total_out += out;
    state->total += out;
    if (state->wrap && out)
        strm->adler = state->check =
            UPDATE(state->check, strm->next_out - out, out);
    strm->data_type = state->bits + (state->last ? 64 : 0) +
                      (state->mode == TYPE ? 128 : 0);
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
        ret = Z_BUF_ERROR;
    return ret;
}

int ZEXPORT inflateEnd(
z_streamp strm)
{
    struct inflate_state FAR *state;
    if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
        return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if (state->window != Z_NULL) ZFREE(strm, state->window);
    ZFREE(strm, strm->state);
    strm->state = Z_NULL;
    Tracev((stderr, "inflate: end\n"));
    return Z_OK;
}

int ZEXPORT inflateSetDictionary(
z_streamp strm,
const Bytef *dictionary,
uInt dictLength)
{
    struct inflate_state FAR *state;
    unsigned long id;

    /* check state */
    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if (state->wrap != 0 && state->mode != DICT)
        return Z_STREAM_ERROR;

    /* check for correct dictionary id */
    if (state->mode == DICT) {
        id = adler32(0L, Z_NULL, 0);
        id = adler32(id, dictionary, dictLength);
        if (id != state->check)
            return Z_DATA_ERROR;
    }

    /* copy dictionary to window */
    if (updatewindow(strm, strm->avail_out)) {
        state->mode = MEM;
        return Z_MEM_ERROR;
    }
    if (dictLength > state->wsize) {
        zmemcpy(state->window, dictionary + dictLength - state->wsize,
                state->wsize);
        state->whave = state->wsize;
    }
    else {
        zmemcpy(state->window + state->wsize - dictLength, dictionary,
                dictLength);
        state->whave = dictLength;
    }
    state->havedict = 1;
    Tracev((stderr, "inflate:   dictionary set\n"));
    return Z_OK;
}

int ZEXPORT inflateGetHeader(
z_streamp strm,
gz_headerp head)
{
    struct inflate_state FAR *state;

    /* check state */
    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;

    /* save header structure */
    state->head = head;
    head->done = 0;
    return Z_OK;
}

local unsigned syncsearch(
unsigned FAR *have,
unsigned char FAR *buf,
unsigned len)
{
    unsigned got;
    unsigned next;

    got = *have;
    next = 0;
    while (next < len && got < 4) {
        if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
            got++;
        else if (buf[next])
            got = 0;
        else
            got = 4 - got;
        next++;
    }
    *have = got;
    return next;
}

int ZEXPORT inflateSync(
z_streamp strm)
{
    unsigned len;               /* number of bytes to look at or looked at */
    unsigned long in, out;      /* temporary to save total_in and total_out */
    unsigned char buf[4];       /* to restore bit buffer to byte string */
    struct inflate_state FAR *state;

    /* check parameters */
    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;

    /* if first time, start search in bit buffer */
    if (state->mode != SYNC) {
        state->mode = SYNC;
        state->hold <<= state->bits & 7;
        state->bits -= state->bits & 7;
        len = 0;
        while (state->bits >= 8) {
            buf[len++] = (unsigned char)(state->hold);
            state->hold >>= 8;
            state->bits -= 8;
        }
        state->have = 0;
        syncsearch(&(state->have), buf, len);
    }

    /* search available input */
    len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
    strm->avail_in -= len;
    strm->next_in += len;
    strm->total_in += len;

    /* return no joy or set up to restart inflate() on a new block */
    if (state->have != 4) return Z_DATA_ERROR;
    in = strm->total_in;  out = strm->total_out;
    inflateReset(strm);
    strm->total_in = in;  strm->total_out = out;
    state->mode = TYPE;
    return Z_OK;
}

int ZEXPORT inflateSyncPoint(
z_streamp strm)
{
    struct inflate_state FAR *state;

    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    return state->mode == STORED && state->bits == 0;
}

int ZEXPORT inflateCopy(
z_streamp dest,
z_streamp source)
{
    struct inflate_state FAR *state;
    struct inflate_state FAR *copy;
    unsigned char FAR *window;
    unsigned wsize;

    /* check input */
    if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
        source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
        return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)source->state;

    /* allocate space */
    copy = (struct inflate_state FAR *)
           ZALLOC(source, 1, sizeof(struct inflate_state));
    if (copy == Z_NULL) return Z_MEM_ERROR;
    window = Z_NULL;
    if (state->window != Z_NULL) {
        window = (unsigned char FAR *)
                 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
        if (window == Z_NULL) {
            ZFREE(source, copy);
            return Z_MEM_ERROR;
        }
    }

    /* copy state */
    zmemcpy(dest, source, sizeof(z_stream));
    zmemcpy(copy, state, sizeof(struct inflate_state));
    if (state->lencode >= state->codes &&
        state->lencode <= state->codes + ENOUGH - 1) {
        copy->lencode = copy->codes + (state->lencode - state->codes);
        copy->distcode = copy->codes + (state->distcode - state->codes);
    }
    copy->next = copy->codes + (state->next - state->codes);
    if (window != Z_NULL) {
        wsize = 1U << state->wbits;
        zmemcpy(window, state->window, wsize);
    }
    copy->window = window;
    dest->state = (struct internal_state FAR *)copy;
    return Z_OK;
}

int inflate_table(
codetype type,
unsigned short FAR *lens,
unsigned codes,
code FAR * FAR *table,
unsigned FAR *bits,
unsigned short FAR *work)
{
    unsigned len;               /* a code's length in bits */
    unsigned sym;               /* index of code symbols */
    unsigned min, max;          /* minimum and maximum code lengths */
    unsigned root;              /* number of index bits for root table */
    unsigned curr;              /* number of index bits for current table */
    unsigned drop;              /* code bits to drop for sub-table */
    int left;                   /* number of prefix codes available */
    unsigned used;              /* code entries in table used */
    unsigned huff;              /* Huffman code */
    unsigned incr;              /* for incrementing code, index */
    unsigned fill;              /* index for replicating entries */
    unsigned low;               /* low bits for current root entry */
    unsigned mask;              /* mask for low root bits */
    code self;                  /* table entry for duplication */
    code FAR *next;             /* next available space in table */
    const unsigned short FAR *base;     /* base value table to use */
    const unsigned short FAR *extra;    /* extra bits table to use */
    int end;                    /* use base and extra for symbol > end */
    unsigned short count[MAXBITS+1];    /* number of codes of each length */
    unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
    static const unsigned short lbase[31] = { /* Length codes 257..285 base */
        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
    static const unsigned short lext[31] = { /* Length codes 257..285 extra */
        16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 201, 196};
    static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
        8193, 12289, 16385, 24577, 0, 0};
    static const unsigned short dext[32] = { /* Distance codes 0..29 extra */
        16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22,
        23, 23, 24, 24, 25, 25, 26, 26, 27, 27,
        28, 28, 29, 29, 64, 64};

    /*
       Process a set of code lengths to create a canonical Huffman code.  The
       code lengths are lens[0..codes-1].  Each length corresponds to the
       symbols 0..codes-1.  The Huffman code is generated by first sorting the
       symbols by length from short to long, and retaining the symbol order
       for codes with equal lengths.  Then the code starts with all zero bits
       for the first code of the shortest length, and the codes are integer
       increments for the same length, and zeros are appended as the length
       increases.  For the deflate format, these bits are stored backwards
       from their more natural integer increment ordering, and so when the
       decoding tables are built in the large loop below, the integer codes
       are incremented backwards.

       This routine assumes, but does not check, that all of the entries in
       lens[] are in the range 0..MAXBITS.  The caller must assure this.
       1..MAXBITS is interpreted as that code length.  zero means that that
       symbol does not occur in this code.

       The codes are sorted by computing a count of codes for each length,
       creating from that a table of starting indices for each length in the
       sorted table, and then entering the symbols in order in the sorted
       table.  The sorted table is work[], with that space being provided by
       the caller.

       The length counts are used for other purposes as well, i.e. finding
       the minimum and maximum length codes, determining if there are any
       codes at all, checking for a valid set of lengths, and looking ahead
       at length counts to determine sub-table sizes when building the
       decoding tables.
     */

    /* accumulate lengths for codes (assumes lens[] all in 0..MAXBITS) */
    for (len = 0; len <= MAXBITS; len++)
        count[len] = 0;
    for (sym = 0; sym < codes; sym++)
        count[lens[sym]]++;

    /* bound code lengths, force root to be within code lengths */
    root = *bits;
    for (max = MAXBITS; max >= 1; max--)
        if (count[max] != 0) break;
    if (root > max) root = max;
    if (max == 0) {                     /* no symbols to code at all */
        self.op = (unsigned char)64;    /* invalid code marker */
        self.bits = (unsigned char)1;
        self.val = (unsigned short)0;
        *(*table)++ = self;             /* make a table to force an error */
        *(*table)++ = self;
        *bits = 1;
        return 0;     /* no symbols, but wait for decoding to report error */
    }
    for (min = 1; min <= MAXBITS; min++)
        if (count[min] != 0) break;
    if (root < min) root = min;

    /* check for an over-subscribed or incomplete set of lengths */
    left = 1;
    for (len = 1; len <= MAXBITS; len++) {
        left <<= 1;
        left -= count[len];
        if (left < 0) return -1;        /* over-subscribed */
    }
    if (left > 0 && (type == CODES || max != 1))
        return -1;                      /* incomplete set */

    /* generate offsets into symbol table for each length for sorting */
    offs[1] = 0;
    for (len = 1; len < MAXBITS; len++)
        offs[len + 1] = offs[len] + count[len];

    /* sort symbols by length, by symbol order within each length */
    for (sym = 0; sym < codes; sym++)
        if (lens[sym] != 0) work[offs[lens[sym]]++] = (unsigned short)sym;

    /*
       Create and fill in decoding tables.  In this loop, the table being
       filled is at next and has curr index bits.  The code being used is huff
       with length len.  That code is converted to an index by dropping drop
       bits off of the bottom.  For codes where len is less than drop + curr,
       those top drop + curr - len bits are incremented through all values to
       fill the table with replicated entries.

       root is the number of index bits for the root table.  When len exceeds
       root, sub-tables are created pointed to by the root entry with an index
       of the low root bits of huff.  This is saved in low to check for when a
       new sub-table should be started.  drop is zero when the root table is
       being filled, and drop is root when sub-tables are being filled.

       When a new sub-table is needed, it is necessary to look ahead in the
       code lengths to determine what size sub-table is needed.  The length
       counts are used for this, and so count[] is decremented as codes are
       entered in the tables.

       used keeps track of how many table entries have been allocated from the
       provided *table space.  It is checked when a LENS table is being made
       against the space in *table, ENOUGH, minus the maximum space needed by
       the worst case distance code, MAXD.  This should never happen, but the
       sufficiency of ENOUGH has not been proven exhaustively, hence the check.
       This assumes that when type == LENS, bits == 9.

       sym increments through all symbols, and the loop terminates when
       all codes of length max, i.e. all codes, have been processed.  This
       routine permits incomplete codes, so another loop after this one fills
       in the rest of the decoding tables with invalid code markers.
     */

    /* set up for code type */
    switch (type) {
    case CODES:
        base = extra = work;    /* dummy value--not used */
        end = 19;
        break;
    case LENS:
        base = lbase;
        base -= 257;
        extra = lext;
        extra -= 257;
        end = 256;
        break;
    default:            /* DISTS */
        base = dbase;
        extra = dext;
        end = -1;
    }

    /* initialize state for loop */
    huff = 0;                   /* starting code */
    sym = 0;                    /* starting code symbol */
    len = min;                  /* starting code length */
    next = *table;              /* current table to fill in */
    curr = root;                /* current table index bits */
    drop = 0;                   /* current bits to drop from code for index */
    low = (unsigned)(-1);       /* trigger new sub-table when len > root */
    used = 1U << root;          /* use root table entries */
    mask = used - 1;            /* mask for comparing low */

    /* check available table space */
    if (type == LENS && used >= ENOUGH - MAXD)
        return 1;

    /* process all codes and make table entries */
    for (;;) {
        /* create table entry */
        self.bits = (unsigned char)(len - drop);
        if ((int)(work[sym]) < end) {
            self.op = (unsigned char)0;
            self.val = work[sym];
        }
        else if ((int)(work[sym]) > end) {
            self.op = (unsigned char)(extra[work[sym]]);
            self.val = base[work[sym]];
        }
        else {
            self.op = (unsigned char)(32 + 64);         /* end of block */
            self.val = 0;
        }

        /* replicate for those indices with low len bits equal to huff */
        incr = 1U << (len - drop);
        fill = 1U << curr;
        min = fill;                 /* save offset to next table */
        do {
            fill -= incr;
            next[(huff >> drop) + fill] = self;
        } while (fill != 0);

        /* backwards increment the len-bit code huff */
        incr = 1U << (len - 1);
        while (huff & incr)
            incr >>= 1;
        if (incr != 0) {
            huff &= incr - 1;
            huff += incr;
        }
        else
            huff = 0;

        /* go to next symbol, update count, len */
        sym++;
        if (--(count[len]) == 0) {
            if (len == max) break;
            len = lens[work[sym]];
        }

        /* create new sub-table if needed */
        if (len > root && (huff & mask) != low) {
            /* if first time, transition to sub-tables */
            if (drop == 0)
                drop = root;

            /* increment past last table */
            next += min;            /* here min is 1 << curr */

            /* determine length of next table */
            curr = len - drop;
            left = (int)(1 << curr);
            while (curr + drop < max) {
                left -= count[curr + drop];
                if (left <= 0) break;
                curr++;
                left <<= 1;
            }

            /* check for enough space */
            used += 1U << curr;
            if (type == LENS && used >= ENOUGH - MAXD)
                return 1;

            /* point entry in root table to sub-table */
            low = huff & mask;
            (*table)[low].op = (unsigned char)curr;
            (*table)[low].bits = (unsigned char)root;
            (*table)[low].val = (unsigned short)(next - *table);
        }
    }

    /*
       Fill in rest of table for incomplete codes.  This loop is similar to the
       loop above in incrementing huff for table indices.  It is assumed that
       len is equal to curr + drop, so there is no loop needed to increment
       through high index bits.  When the current sub-table is filled, the loop
       drops back to the root table to fill in any remaining entries there.
     */
    self.op = (unsigned char)64;                /* invalid code marker */
    self.bits = (unsigned char)(len - drop);
    self.val = (unsigned short)0;
    while (huff != 0) {
        /* when done with sub-table, drop back to root table */
        if (drop != 0 && (huff & mask) != low) {
            drop = 0;
            len = root;
            next = *table;
            self.bits = (unsigned char)len;
        }

        /* put invalid code marker in table */
        next[huff >> drop] = self;

        /* backwards increment the len-bit code huff */
        incr = 1U << (len - 1);
        while (huff & incr)
            incr >>= 1;
        if (incr != 0) {
            huff &= incr - 1;
            huff += incr;
        }
        else
            huff = 0;
    }

    /* set return parameters */
    *table += used;
    *bits = root;
    return 0;
}

local void send_bits(
    deflate_state *s,
    int value,  /* value to send */
    int length) /* number of bits */
{
    Tracevv((stderr," l %2d v %4x ", length, value));
    Assert(length > 0 && length <= 15, "invalid length");
    s->bits_sent += (ulg)length;

    /* If not enough room in bi_buf, use (valid) bits from bi_buf and
     * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
     * unused bits in value.
     */
    if (s->bi_valid > (int)Buf_size - length) {
        s->bi_buf |= (value << s->bi_valid);
        put_short(s, s->bi_buf);
        s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
        s->bi_valid += length - Buf_size;
    } else {
        s->bi_buf |= value << s->bi_valid;
        s->bi_valid += length;
    }
}
#else /* !DEBUG */

#define send_bits(s, value, length) \
{ int len = length;\
  if (s->bi_valid > (int)Buf_size - len) {\
    int val = value;\
    s->bi_buf |= (val << s->bi_valid);\
    put_short(s, s->bi_buf);\
    s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
    s->bi_valid += len - Buf_size;\
  } else {\
    s->bi_buf |= (value) << s->bi_valid;\
    s->bi_valid += len;\
  }\
}

local void tr_static_init( void )
{
#if defined(GEN_TREES_H) || !defined(STDC)
    static int static_init_done = 0;
    int n;        /* iterates over tree elements */
    int bits;     /* bit counter */
    int length;   /* length value */
    int code;     /* code value */
    int dist;     /* distance index */
    ush bl_count[MAX_BITS+1];
    /* number of codes at each bit length for an optimal tree */

    if (static_init_done) return;

    /* For some embedded targets, global variables are not initialized: */
    static_l_desc.static_tree = static_ltree;
    static_l_desc.extra_bits = extra_lbits;
    static_d_desc.static_tree = static_dtree;
    static_d_desc.extra_bits = extra_dbits;
    static_bl_desc.extra_bits = extra_blbits;

    /* Initialize the mapping length (0..255) -> length code (0..28) */
    length = 0;
    for (code = 0; code < LENGTH_CODES-1; code++) {
        base_length[code] = length;
        for (n = 0; n < (1< dist code (0..29) */
    dist = 0;
    for (code = 0 ; code < 16; code++) {
        base_dist[code] = dist;
        for (n = 0; n < (1<>= 7; /* from now on, all distances are divided by 128 */
    for ( ; code < D_CODES; code++) {
        base_dist[code] = dist << 7;
        for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
            _dist_code[256 + dist++] = (uch)code;
        }
    }
    Assert (dist == 256, "tr_static_init: 256+dist != 512");

    /* Construct the codes of the static literal tree */
    for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
    n = 0;
    while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
    while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
    while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
    while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
    /* Codes 286 and 287 do not exist, but we must include them in the
     * tree construction to get a canonical Huffman tree (longest code
     * all ones)
     */
    gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);

    /* The static distance tree is trivial: */
    for (n = 0; n < D_CODES; n++) {
        static_dtree[n].Len = 5;
        static_dtree[n].Code = bi_reverse((unsigned)n, 5);
    }
    static_init_done = 1;

#  ifdef GEN_TREES_H
    gen_trees_header();
#  endif
#endif /* defined(GEN_TREES_H) || !defined(STDC) */
}

/* ===========================================================================
 * Genererate the file trees.h describing the static trees.
 */
#ifdef GEN_TREES_H
#  ifndef DEBUG
#    include 
#  endif

#  define SEPARATOR(i, last, width) \
      ((i) == (last)? "\n};\n\n" :    \
       ((i) % (width) == (width)-1 ? ",\n" : ", "))

void gen_trees_header()
{
    FILE *header = fopen("trees.h", "w");
    int i;

    Assert (header != NULL, "Can't open trees.h");
    fprintf(header,
            "/* header created automatically with -DGEN_TREES_H */\n\n");

    fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
    for (i = 0; i < L_CODES+2; i++) {
        fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
                static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
    }

    fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
    for (i = 0; i < D_CODES; i++) {
        fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
                static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
    }

    fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n");
    for (i = 0; i < DIST_CODE_LEN; i++) {
        fprintf(header, "%2u%s", _dist_code[i],
                SEPARATOR(i, DIST_CODE_LEN-1, 20));
    }

    fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
    for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
        fprintf(header, "%2u%s", _length_code[i],
                SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
    }

    fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
    for (i = 0; i < LENGTH_CODES; i++) {
        fprintf(header, "%1u%s", base_length[i],
                SEPARATOR(i, LENGTH_CODES-1, 20));
    }

    fprintf(header, "local const int base_dist[D_CODES] = {\n");
    for (i = 0; i < D_CODES; i++) {
        fprintf(header, "%5u%s", base_dist[i],
                SEPARATOR(i, D_CODES-1, 10));
    }

    fclose(header);
}

void _tr_init(
    deflate_state *s)
{
    tr_static_init();

    s->l_desc.dyn_tree = s->dyn_ltree;
    s->l_desc.stat_desc = &static_l_desc;

    s->d_desc.dyn_tree = s->dyn_dtree;
    s->d_desc.stat_desc = &static_d_desc;

    s->bl_desc.dyn_tree = s->bl_tree;
    s->bl_desc.stat_desc = &static_bl_desc;

    s->bi_buf = 0;
    s->bi_valid = 0;
    s->last_eob_len = 8; /* enough lookahead for inflate */
#ifdef DEBUG
    s->compressed_len = 0L;
    s->bits_sent = 0L;
#endif

    /* Initialize the first block of the first file: */
    init_block(s);
}

local void init_block(
    deflate_state *s)
{
    int n; /* iterates over tree elements */

    /* Initialize the trees. */
    for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
    for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
    for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;

    s->dyn_ltree[END_BLOCK].Freq = 1;
    s->opt_len = s->static_len = 0L;
    s->last_lit = s->matches = 0;
}

#define SMALLEST 1
/* Index within the heap array of least frequent node in the Huffman tree */


/* ===========================================================================
 * Remove the smallest element from the heap and recreate the heap with
 * one less element. Updates heap and heap_len.
 */
#define pqremove(s, tree, top) \
{\
    top = s->heap[SMALLEST]; \
    s->heap[SMALLEST] = s->heap[s->heap_len--]; \
    pqdownheap(s, tree, SMALLEST); \
}

/* ===========================================================================
 * Compares to subtrees, using the tree depth as tie breaker when
 * the subtrees have equal frequency. This minimizes the worst case length.
 */
#define smaller(tree, n, m, depth) \
   (tree[n].Freq < tree[m].Freq || \
   (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))

local void pqdownheap(
    deflate_state *s,
    ct_data *tree,  /* the tree to restore */
    int k)               /* node to move down */
{
    int v = s->heap[k];
    int j = k << 1;  /* left son of k */
    while (j <= s->heap_len) {
        /* Set j to the smallest of the two sons: */
        if (j < s->heap_len &&
            smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
            j++;
        }
        /* Exit if v is smaller than both sons */
        if (smaller(tree, v, s->heap[j], s->depth)) break;

        /* Exchange v with the smallest son */
        s->heap[k] = s->heap[j];  k = j;

        /* And continue down the tree, setting j to the left son of k */
        j <<= 1;
    }
    s->heap[k] = v;
}

local void gen_bitlen(
    deflate_state *s,
    tree_desc *desc)    /* the tree descriptor */
{
    ct_data *tree        = desc->dyn_tree;
    int max_code         = desc->max_code;
    const ct_data *stree = desc->stat_desc->static_tree;
    const intf *extra    = desc->stat_desc->extra_bits;
    int base             = desc->stat_desc->extra_base;
    int max_length       = desc->stat_desc->max_length;
    int h;              /* heap index */
    int n, m;           /* iterate over the tree elements */
    int bits;           /* bit length */
    int xbits;          /* extra bits */
    ush f;              /* frequency */
    int overflow = 0;   /* number of elements with bit length too large */

    for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;

    /* In a first pass, compute the optimal bit lengths (which may
     * overflow in the case of the bit length tree).
     */
    tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */

    for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
        n = s->heap[h];
        bits = tree[tree[n].Dad].Len + 1;
        if (bits > max_length) bits = max_length, overflow++;
        tree[n].Len = (ush)bits;
        /* We overwrite tree[n].Dad which is no longer needed */

        if (n > max_code) continue; /* not a leaf node */

        s->bl_count[bits]++;
        xbits = 0;
        if (n >= base) xbits = extra[n-base];
        f = tree[n].Freq;
        s->opt_len += (ulg)f * (bits + xbits);
        if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
    }
    if (overflow == 0) return;

    Trace((stderr,"\nbit length overflow\n"));
    /* This happens for example on obj2 and pic of the Calgary corpus */

    /* Find the first bit length which could increase: */
    do {
        bits = max_length-1;
        while (s->bl_count[bits] == 0) bits--;
        s->bl_count[bits]--;      /* move one leaf down the tree */
        s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
        s->bl_count[max_length]--;
        /* The brother of the overflow item also moves one step up,
         * but this does not affect bl_count[max_length]
         */
        overflow -= 2;
    } while (overflow > 0);

    /* Now recompute all bit lengths, scanning in increasing frequency.
     * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
     * lengths instead of fixing only the wrong ones. This idea is taken
     * from 'ar' written by Haruhiko Okumura.)
     */
    for (bits = max_length; bits != 0; bits--) {
        n = s->bl_count[bits];
        while (n != 0) {
            m = s->heap[--h];
            if (m > max_code) continue;
            if ((unsigned) tree[m].Len != (unsigned) bits) {
                Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
                s->opt_len += ((long)bits - (long)tree[m].Len)
                              *(long)tree[m].Freq;
                tree[m].Len = (ush)bits;
            }
            n--;
        }
    }
}

local void gen_codes (
    ct_data *tree,             /* the tree to decorate */
    int max_code,              /* largest code with non zero frequency */
    ushf *bl_count)            /* number of codes at each bit length */
{
    ush next_code[MAX_BITS+1]; /* next code value for each bit length */
    ush code = 0;              /* running code value */
    int bits;                  /* bit index */
    int n;                     /* code index */

    /* The distribution counts are first used to generate the code values
     * without bit reversal.
     */
    for (bits = 1; bits <= MAX_BITS; bits++) {
        next_code[bits] = code = (code + bl_count[bits-1]) << 1;
    }
    /* Check that the bit counts in bl_count are consistent. The last code
     * must be all ones.
     */
    Assert (code + bl_count[MAX_BITS]-1 == (1<

local void build_tree(
    deflate_state *s,
    tree_desc *desc) /* the tree descriptor */
{
    ct_data *tree         = desc->dyn_tree;
    const ct_data *stree  = desc->stat_desc->static_tree;
    int elems             = desc->stat_desc->elems;
    int n, m;          /* iterate over heap elements */
    int max_code = -1; /* largest code with non zero frequency */
    int node;          /* new node being created */

    /* Construct the initial heap, with least frequent element in
     * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
     * heap[0] is not used.
     */
    s->heap_len = 0, s->heap_max = HEAP_SIZE;

    for (n = 0; n < elems; n++) {
        if (tree[n].Freq != 0) {
            s->heap[++(s->heap_len)] = max_code = n;
            s->depth[n] = 0;
        } else {
            tree[n].Len = 0;
        }
    }

    /* The pkzip format requires that at least one distance code exists,
     * and that at least one bit should be sent even if there is only one
     * possible code. So to avoid special checks later on we force at least
     * two codes of non zero frequency.
     */
    while (s->heap_len < 2) {
        node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
        tree[node].Freq = 1;
        s->depth[node] = 0;
        s->opt_len--; if (stree) s->static_len -= stree[node].Len;
        /* node is 0 or 1 so it does not have extra bits */
    }
    desc->max_code = max_code;

    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
     * establish sub-heaps of increasing lengths:
     */
    for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);

    /* Construct the Huffman tree by repeatedly combining the least two
     * frequent nodes.
     */
    node = elems;              /* next internal node of the tree */
    do {
        pqremove(s, tree, n);  /* n = node of least frequency */
        m = s->heap[SMALLEST]; /* m = node of next least frequency */

        s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
        s->heap[--(s->heap_max)] = m;

        /* Create a new node father of n and m */
        tree[node].Freq = tree[n].Freq + tree[m].Freq;
        s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?
                                s->depth[n] : s->depth[m]) + 1);
        tree[n].Dad = tree[m].Dad = (ush)node;
#ifdef DUMP_BL_TREE
        if (tree == s->bl_tree) {
            fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
                    node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
        }
#endif
        /* and insert the new node in the heap */
        s->heap[SMALLEST] = node++;
        pqdownheap(s, tree, SMALLEST);

    } while (s->heap_len >= 2);

    s->heap[--(s->heap_max)] = s->heap[SMALLEST];

    /* At this point, the fields freq and dad are set. We can now
     * generate the bit lengths.
     */
    gen_bitlen(s, (tree_desc *)desc);

    /* The field len is now set, we can generate the bit codes */
    gen_codes ((ct_data *)tree, max_code, s->bl_count);
}

local void scan_tree (
    deflate_state *s,
    ct_data *tree,   /* the tree to be scanned */
    int max_code)    /* and its largest code of non zero frequency */
{
    int n;                     /* iterates over all tree elements */
    int prevlen = -1;          /* last emitted length */
    int curlen;                /* length of current code */
    int nextlen = tree[0].Len; /* length of next code */
    int count = 0;             /* repeat count of the current code */
    int max_count = 7;         /* max repeat count */
    int min_count = 4;         /* min repeat count */

    if (nextlen == 0) max_count = 138, min_count = 3;
    tree[max_code+1].Len = (ush)0xffff; /* guard */

    for (n = 0; n <= max_code; n++) {
        curlen = nextlen; nextlen = tree[n+1].Len;
        if (++count < max_count && curlen == nextlen) {
            continue;
        } else if (count < min_count) {
            s->bl_tree[curlen].Freq += count;
        } else if (curlen != 0) {
            if (curlen != prevlen) s->bl_tree[curlen].Freq++;
            s->bl_tree[REP_3_6].Freq++;
        } else if (count <= 10) {
            s->bl_tree[REPZ_3_10].Freq++;
        } else {
            s->bl_tree[REPZ_11_138].Freq++;
        }
        count = 0; prevlen = curlen;
        if (nextlen == 0) {
            max_count = 138, min_count = 3;
        } else if (curlen == nextlen) {
            max_count = 6, min_count = 3;
        } else {
            max_count = 7, min_count = 4;
        }
    }
}

local void send_tree (
    deflate_state *s,
    ct_data *tree, /* the tree to be scanned */
    int max_code)       /* and its largest code of non zero frequency */
{
    int n;                     /* iterates over all tree elements */
    int prevlen = -1;          /* last emitted length */
    int curlen;                /* length of current code */
    int nextlen = tree[0].Len; /* length of next code */
    int count = 0;             /* repeat count of the current code */
    int max_count = 7;         /* max repeat count */
    int min_count = 4;         /* min repeat count */

    /* tree[max_code+1].Len = -1; */  /* guard already set */
    if (nextlen == 0) max_count = 138, min_count = 3;

    for (n = 0; n <= max_code; n++) {
        curlen = nextlen; nextlen = tree[n+1].Len;
        if (++count < max_count && curlen == nextlen) {
            continue;
        } else if (count < min_count) {
            do { send_code(s, curlen, s->bl_tree); } while (--count != 0);

        } else if (curlen != 0) {
            if (curlen != prevlen) {
                send_code(s, curlen, s->bl_tree); count--;
            }
            Assert(count >= 3 && count <= 6, " 3_6?");
            send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);

        } else if (count <= 10) {
            send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);

        } else {
            send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
        }
        count = 0; prevlen = curlen;
        if (nextlen == 0) {
            max_count = 138, min_count = 3;
        } else if (curlen == nextlen) {
            max_count = 6, min_count = 3;
        } else {
            max_count = 7, min_count = 4;
        }
    }
}

local int build_bl_tree(
    deflate_state *s)
{
    int max_blindex;  /* index of last bit length code of non zero freq */

    /* Determine the bit length frequencies for literal and distance trees */
    scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
    scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);

    /* Build the bit length tree: */
    build_tree(s, (tree_desc *)(&(s->bl_desc)));
    /* opt_len now includes the length of the tree representations, except
     * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
     */

    /* Determine the number of bit length codes to send. The pkzip format
     * requires that at least 4 bit length codes be sent. (appnote.txt says
     * 3 but the actual value used is 4.)
     */
    for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
        if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
    }
    /* Update opt_len to include the bit length tree and counts */
    s->opt_len += 3*(max_blindex+1) + 5+5+4;
    Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
            s->opt_len, s->static_len));

    return max_blindex;
}

local void send_all_trees(
    deflate_state *s,
    int lcodes, int dcodes, int blcodes) /* number of codes for each tree */
{
    int rank;                    /* index in bl_order */

    Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
    Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
            "too many codes");
    Tracev((stderr, "\nbl counts: "));
    send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
    send_bits(s, dcodes-1,   5);
    send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */
    for (rank = 0; rank < blcodes; rank++) {
        Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
        send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
    }
    Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));

    send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
    Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));

    send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
    Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
}

void _tr_stored_block(
    deflate_state *s,
    charf *buf,       /* input block */
    ulg stored_len,   /* length of input block */
    int eof)          /* true if this is the last block for a file */
{
    send_bits(s, (STORED_BLOCK<<1)+eof, 3);  /* send block type */
#ifdef DEBUG
    s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
    s->compressed_len += (stored_len + 4) << 3;
#endif
    copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
}

void _tr_align(
    deflate_state *s)
{
    send_bits(s, STATIC_TREES<<1, 3);
    send_code(s, END_BLOCK, static_ltree);
#ifdef DEBUG
    s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
#endif
    bi_flush(s);
    /* Of the 10 bits for the empty block, we have already sent
     * (10 - bi_valid) bits. The lookahead for the last real code (before
     * the EOB of the previous block) was thus at least one plus the length
     * of the EOB plus what we have just sent of the empty static block.
     */
    if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
        send_bits(s, STATIC_TREES<<1, 3);
        send_code(s, END_BLOCK, static_ltree);
#ifdef DEBUG
        s->compressed_len += 10L;
#endif
        bi_flush(s);
    }
    s->last_eob_len = 7;
}

void _tr_flush_block(
    deflate_state *s,
    charf *buf,       /* input block, or NULL if too old */
    ulg stored_len,   /* length of input block */
    int eof)          /* true if this is the last block for a file */
{
    ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
    int max_blindex = 0;  /* index of last bit length code of non zero freq */

    /* Build the Huffman trees unless a stored block is forced */
    if (s->level > 0) {

        /* Check if the file is binary or text */
        if (stored_len > 0 && s->strm->data_type == Z_UNKNOWN)
            set_data_type(s);

        /* Construct the literal and distance trees */
        build_tree(s, (tree_desc *)(&(s->l_desc)));
        Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
                s->static_len));

        build_tree(s, (tree_desc *)(&(s->d_desc)));
        Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
                s->static_len));
        /* At this point, opt_len and static_len are the total bit lengths of
         * the compressed block data, excluding the tree representations.
         */

        /* Build the bit length tree for the above two trees, and get the index
         * in bl_order of the last bit length code to send.
         */
        max_blindex = build_bl_tree(s);

        /* Determine the best encoding. Compute the block lengths in bytes. */
        opt_lenb = (s->opt_len+3+7)>>3;
        static_lenb = (s->static_len+3+7)>>3;

        Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
                opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
                s->last_lit));

        if (static_lenb <= opt_lenb) opt_lenb = static_lenb;

    } else {
        Assert(buf != (char*)0, "lost buf");
        opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
    }

#ifdef FORCE_STORED
    if (buf != (char*)0) { /* force stored block */
#else
    if (stored_len+4 <= opt_lenb && buf != (char*)0) {
                       /* 4: two words for the lengths */
#endif
        /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
         * Otherwise we can't have processed more than WSIZE input bytes since
         * the last block flush, because compression would have been
         * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
         * transform a block into a stored block.
         */
        _tr_stored_block(s, buf, stored_len, eof);

#ifdef FORCE_STATIC
    } else if (static_lenb >= 0) { /* force static trees */
#else
    } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
#endif
        send_bits(s, (STATIC_TREES<<1)+eof, 3);
        compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
#ifdef DEBUG
        s->compressed_len += 3 + s->static_len;
#endif
    } else {
        send_bits(s, (DYN_TREES<<1)+eof, 3);
        send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
                       max_blindex+1);
        compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
#ifdef DEBUG
        s->compressed_len += 3 + s->opt_len;
#endif
    }
    Assert (s->compressed_len == s->bits_sent, "bad compressed size");
    /* The above check is made mod 2^32, for files larger than 512 MB
     * and uLong implemented on 32 bits.
     */
    init_block(s);

    if (eof) {
        bi_windup(s);
#ifdef DEBUG
        s->compressed_len += 7;  /* align on byte boundary */
#endif
    }
    Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
           s->compressed_len-7*eof));
}

/* ===========================================================================
 * Save the match info and tally the frequency counts. Return true if
 * the current block must be flushed.
 */
int _tr_tally (
    deflate_state *s,
    unsigned dist,  /* distance of matched string */
    unsigned lc)    /* match length-MIN_MATCH or unmatched char (if dist==0) */
{
    s->d_buf[s->last_lit] = (ush)dist;
    s->l_buf[s->last_lit++] = (uch)lc;
    if (dist == 0) {
        /* lc is the unmatched char */
        s->dyn_ltree[lc].Freq++;
    } else {
        s->matches++;
        /* Here, lc is the match length - MIN_MATCH */
        dist--;             /* dist = match distance - 1 */
        Assert((ush)dist < (ush)MAX_DIST(s) &&
               (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
               (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");

        s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
        s->dyn_dtree[d_code(dist)].Freq++;
    }

#ifdef TRUNCATE_BLOCK
    /* Try to guess if it is profitable to stop the current block here */
    if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
        /* Compute an upper bound for the compressed length */
        ulg out_length = (ulg)s->last_lit*8L;
        ulg in_length = (ulg)((long)s->strstart - s->block_start);
        int dcode;
        for (dcode = 0; dcode < D_CODES; dcode++) {
            out_length += (ulg)s->dyn_dtree[dcode].Freq *
                (5L+extra_dbits[dcode]);
        }
        out_length >>= 3;
        Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
               s->last_lit, in_length, out_length,
               100L - out_length*100L/in_length));
        if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
    }
#endif
    return (s->last_lit == s->lit_bufsize-1);
    /* We avoid equality with lit_bufsize because of wraparound at 64K
     * on 16 bit machines and because stored blocks are restricted to
     * 64K-1 bytes.
     */
}

/* ===========================================================================
 * Send the block data compressed using the given Huffman trees
 */
local void compress_block(
    deflate_state *s,
    ct_data *ltree, /* literal tree */
    ct_data *dtree) /* distance tree */
{
    unsigned dist;      /* distance of matched string */
    int lc;             /* match length or unmatched char (if dist == 0) */
    unsigned lx = 0;    /* running index in l_buf */
    unsigned code;      /* the code to send */
    int extra;          /* number of extra bits to send */

    if (s->last_lit != 0) do {
        dist = s->d_buf[lx];
        lc = s->l_buf[lx++];
        if (dist == 0) {
            send_code(s, lc, ltree); /* send a literal byte */
            Tracecv(isgraph(lc), (stderr," '%c' ", lc));
        } else {
            /* Here, lc is the match length - MIN_MATCH */
            code = _length_code[lc];
            send_code(s, code+LITERALS+1, ltree); /* send the length code */
            extra = extra_lbits[code];
            if (extra != 0) {
                lc -= base_length[code];
                send_bits(s, lc, extra);       /* send the extra length bits */
            }
            dist--; /* dist is now the match distance - 1 */
            code = d_code(dist);
            Assert (code < D_CODES, "bad d_code");

            send_code(s, code, dtree);       /* send the distance code */
            extra = extra_dbits[code];
            if (extra != 0) {
                dist -= base_dist[code];
                send_bits(s, dist, extra);   /* send the extra distance bits */
            }
        } /* literal or match pair ? */

        /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
        Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
               "pendingBuf overflow");

    } while (lx < s->last_lit);

    send_code(s, END_BLOCK, ltree);
    s->last_eob_len = ltree[END_BLOCK].Len;
}

/* ===========================================================================
 * Set the data type to BINARY or TEXT, using a crude approximation:
 * set it to Z_TEXT if all symbols are either printable characters (33 to 255)
 * or white spaces (9 to 13, or 32); or set it to Z_BINARY otherwise.
 * IN assertion: the fields Freq of dyn_ltree are set.
 */
local void set_data_type(
    deflate_state *s)
{
    int n;

    for (n = 0; n < 9; n++)
        if (s->dyn_ltree[n].Freq != 0)
            break;
    if (n == 9)
        for (n = 14; n < 32; n++)
            if (s->dyn_ltree[n].Freq != 0)
                break;
    s->strm->data_type = (n == 32) ? Z_TEXT : Z_BINARY;
}

/* ===========================================================================
 * Reverse the first len bits of a code, using straightforward code (a faster
 * method would use a table)
 * IN assertion: 1 <= len <= 15
 */
local unsigned bi_reverse(
    unsigned code, /* the value to invert */
    int len)       /* its bit length */
{
    register unsigned res = 0;
    do {
        res |= code & 1;
        code >>= 1, res <<= 1;
    } while (--len > 0);
    return res >> 1;
}

/* ===========================================================================
 * Flush the bit buffer, keeping at most 7 bits in it.
 */
local void bi_flush(
    deflate_state *s)
{
    if (s->bi_valid == 16) {
        put_short(s, s->bi_buf);
        s->bi_buf = 0;
        s->bi_valid = 0;
    } else if (s->bi_valid >= 8) {
        put_byte(s, (Byte)s->bi_buf);
        s->bi_buf >>= 8;
        s->bi_valid -= 8;
    }
}

/* ===========================================================================
 * Flush the bit buffer and align the output on a byte boundary
 */
local void bi_windup(
    deflate_state *s)
{
    if (s->bi_valid > 8) {
        put_short(s, s->bi_buf);
    } else if (s->bi_valid > 0) {
        put_byte(s, (Byte)s->bi_buf);
    }
    s->bi_buf = 0;
    s->bi_valid = 0;
#ifdef DEBUG
    s->bits_sent = (s->bits_sent+7) & ~7;
#endif
}

/* ===========================================================================
 * Copy a stored block, storing first the length and its
 * one's complement if requested.
 */
local void copy_block(
    deflate_state *s,
    charf    *buf,    /* the input data */
    unsigned len,     /* its length */
    int      header)  /* true if block header must be written */
{
    bi_windup(s);        /* align on byte boundary */
    s->last_eob_len = 8; /* enough lookahead for inflate */

    if (header) {
        put_short(s, (ush)len);
        put_short(s, (ush)~len);
#ifdef DEBUG
        s->bits_sent += 2*16;
#endif
    }
#ifdef DEBUG
    s->bits_sent += (ulg)len<<3;
#endif
    while (len--) {
        put_byte(s, *buf++);
    }
}

     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
   enough memory, Z_BUF_ERROR if there was not enough room in the output
   buffer, or Z_DATA_ERROR if the input data was corrupted.
*/
int ZEXPORT uncompress (
    Bytef *dest,
    uLongf *destLen,
    const Bytef *source,
    uLong sourceLen)
{
    z_stream stream;
    int err;

    stream.next_in = (Bytef*)source;
    stream.avail_in = (uInt)sourceLen;
    /* Check for source > 64K on 16-bit machine: */
    if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;

    stream.next_out = dest;
    stream.avail_out = (uInt)*destLen;
    if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;

    stream.zalloc = (alloc_func)0;
    stream.zfree = (free_func)0;

    err = inflateInit(&stream);
    if (err != Z_OK) return err;

    err = inflate(&stream, Z_FINISH);
    if (err != Z_STREAM_END) {
        inflateEnd(&stream);
        if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0))
            return Z_DATA_ERROR;
        return err;
    }
    *destLen = stream.total_out;

    err = inflateEnd(&stream);
    return err;
}

const char * ZEXPORT zlibVersion( void )
{
    return ZLIB_VERSION;
}

uLong ZEXPORT zlibCompileFlags( void )
{
    uLong flags;

    flags = 0;
    switch (sizeof(uInt)) {
    case 2:     break;
    case 4:     flags += 1;     break;
    case 8:     flags += 2;     break;
    default:    flags += 3;
    }
    switch (sizeof(uLong)) {
    case 2:     break;
    case 4:     flags += 1 << 2;        break;
    case 8:     flags += 2 << 2;        break;
    default:    flags += 3 << 2;
    }
    switch (sizeof(voidpf)) {
    case 2:     break;
    case 4:     flags += 1 << 4;        break;
    case 8:     flags += 2 << 4;        break;
    default:    flags += 3 << 4;
    }
    switch (sizeof(z_off_t)) {
    case 2:     break;
    case 4:     flags += 1 << 6;        break;
    case 8:     flags += 2 << 6;        break;
    default:    flags += 3 << 6;
    }
#ifdef DEBUG
    flags += 1 << 8;
#endif
#if defined(ASMV) || defined(ASMINF)
    flags += 1 << 9;
#endif
#ifdef ZLIB_WINAPI
    flags += 1 << 10;
#endif
#ifdef BUILDFIXED
    flags += 1 << 12;
#endif
#ifdef DYNAMIC_CRC_TABLE
    flags += 1 << 13;
#endif
#ifdef NO_GZCOMPRESS
    flags += 1L << 16;
#endif
#ifdef NO_GZIP
    flags += 1L << 17;
#endif
#ifdef PKZIP_BUG_WORKAROUND
    flags += 1L << 20;
#endif
#ifdef FASTEST
    flags += 1L << 21;
#endif
#ifdef STDC
#  ifdef NO_vsnprintf
        flags += 1L << 25;
#    ifdef HAS_vsprintf_void
        flags += 1L << 26;
#    endif
#  else
#    ifdef HAS_vsnprintf_void
        flags += 1L << 26;
#    endif
#  endif
#else
        flags += 1L << 24;
#  ifdef NO_snprintf
        flags += 1L << 25;
#    ifdef HAS_sprintf_void
        flags += 1L << 26;
#    endif
#  else
#    ifdef HAS_snprintf_void
        flags += 1L << 26;
#    endif
#  endif
#endif
    return flags;
}

#ifdef DEBUG

#  ifndef verbose
#    define verbose 0
#  endif
int z_verbose = verbose;

void z_error (m)
    char *m;
{
    fprintf(stderr, "%s\n", m);
    exit(1);
}

const char * ZEXPORT zError(
    int err)
{
    return ERR_MSG(err);
}

#if defined(_WINCE)
    /* The Microsoft C Run-Time Library for Windows CE doesn't have
     * errno.  We define it as a global variable to simplify porting.
     * Its value is always 0 and should not be used.
     */
    int errno = 0;
#endif

#ifndef HAVE_MEMCPY

void zmemcpy(dest, source, len)
    Bytef* dest;
    const Bytef* source;
    uInt  len;
{
    if (len == 0) return;
    do {
        *dest++ = *source++; /* ??? to be unrolled */
    } while (--len != 0);
}

int zmemcmp(s1, s2, len)
    const Bytef* s1;
    const Bytef* s2;
    uInt  len;
{
    uInt j;

    for (j = 0; j < len; j++) {
        if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
    }
    return 0;
}

void zmemzero(dest, len)
    Bytef* dest;
    uInt  len;
{
    if (len == 0) return;
    do {
        *dest++ = 0;  /* ??? to be unrolled */
    } while (--len != 0);
}
#endif


#ifdef SYS16BIT

#ifdef __TURBOC__
/* Turbo C in 16-bit mode */

#  define MY_ZCALLOC

/* Turbo C malloc() does not allow dynamic allocation of 64K bytes
 * and farmalloc(64K) returns a pointer with an offset of 8, so we
 * must fix the pointer. Warning: the pointer must be put back to its
 * original form in order to free it, use zcfree().
 */

#define MAX_PTR 10
/* 10*64K = 640K */

local int next_ptr = 0;

typedef struct ptr_table_s {
    voidpf org_ptr;
    voidpf new_ptr;
} ptr_table;

local ptr_table table[MAX_PTR];

voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
{
    voidpf buf = opaque; /* just to make some compilers happy */
    ulg bsize = (ulg)items*size;

    /* If we allocate less than 65520 bytes, we assume that farmalloc
     * will return a usable pointer which doesn't have to be normalized.
     */
    if (bsize < 65520L) {
        buf = farmalloc(bsize);
        if (*(ush*)&buf != 0) return buf;
    } else {
        buf = farmalloc(bsize + 16L);
    }
    if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
    table[next_ptr].org_ptr = buf;

    /* Normalize the pointer to seg:0 */
    *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
    *(ush*)&buf = 0;
    table[next_ptr++].new_ptr = buf;
    return buf;
}

void  zcfree (voidpf opaque, voidpf ptr)
{
    int n;
    if (*(ush*)&ptr != 0) { /* object < 64K */
        farfree(ptr);
        return;
    }
    /* Find the original pointer */
    for (n = 0; n < next_ptr; n++) {
        if (ptr != table[n].new_ptr) continue;

        farfree(table[n].org_ptr);
        while (++n < next_ptr) {
            table[n-1] = table[n];
        }
        next_ptr--;
        return;
    }
    ptr = opaque; /* just to make some compilers happy */
    Assert(0, "zcfree: ptr not found");
}

voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
{
    if (opaque) opaque = 0; /* to make compiler happy */
    return _halloc((long)items, size);
}

void  zcfree (voidpf opaque, voidpf ptr)
{
    if (opaque) opaque = 0; /* to make compiler happy */
    _hfree(ptr);
}

#endif /* M_I86 */

#endif /* SYS16BIT */


#ifndef MY_ZCALLOC /* Any system without a special alloc function */

#ifndef STDC
extern voidp  malloc OF((uInt size));
extern voidp  calloc OF((uInt items, uInt size));
extern void   free   OF((voidpf ptr));

voidpf zcalloc (
    voidpf opaque,
    unsigned items,
    unsigned size)
{
    if (opaque) items += size - size; /* make compiler happy */
    return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
                              (voidpf)calloc(items, size);
}

void  zcfree (
    voidpf opaque,
    voidpf ptr)
{
    free(ptr);
    if (opaque) return; /* make compiler happy */
}