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/*

  Copyright (c) 1990-2008 Info-ZIP.  All rights reserved.

  See the accompanying file LICENSE, version 2007-Mar-04 or later

  (the contents of which are also included in unzip.h) for terms of use.

  If, for some reason, all these files are missing, the Info-ZIP license

  also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html

*/

/* inflate.c -- by Mark Adler

   version c17e, 30 Mar 2007 */

/* Copyright history:

   - Starting with UnZip 5.41 of 16-April-2000, this source file

     is covered by the Info-Zip LICENSE cited above.

   - Prior versions of this source file, found in UnZip source packages

     up to UnZip 5.40, were put in the public domain.

     The original copyright note by Mark Adler was:

         "You can do whatever you like with this source file,

         though I would prefer that if you modify it and

         redistribute it that you include comments to that effect

         with your name and the date.  Thank you."

   History:

   vers    date          who           what

   ----  ---------  --------------  ------------------------------------

    a    ~~ Feb 92  M. Adler        used full (large, one-step) lookup table

    b1   21 Mar 92  M. Adler        first version with partial lookup tables

    b2   21 Mar 92  M. Adler        fixed bug in fixed-code blocks

    b3   22 Mar 92  M. Adler        sped up match copies, cleaned up some

    b4   25 Mar 92  M. Adler        added prototypes; removed window[] (now

                                    is the responsibility of unzip.h--also

                                    changed name to slide[]), so needs diffs

                                    for unzip.c and unzip.h (this allows

                                    compiling in the small model on MSDOS);

                                    fixed cast of q in huft_build();

    b5   26 Mar 92  M. Adler        got rid of unintended macro recursion.

    b6   27 Mar 92  M. Adler        got rid of nextbyte() routine.  fixed

                                    bug in inflate_fixed().

    c1   30 Mar 92  M. Adler        removed lbits, dbits environment variables.

                                    changed BMAX to 16 for explode.  Removed

                                    OUTB usage, and replaced it with flush()--

                                    this was a 20% speed improvement!  Added

                                    an explode.c (to replace unimplod.c) that

                                    uses the huft routines here.  Removed

                                    register union.

    c2    4 Apr 92  M. Adler        fixed bug for file sizes a multiple of 32k.

    c3   10 Apr 92  M. Adler        reduced memory of code tables made by

                                    huft_build significantly (factor of two to

                                    three).

    c4   15 Apr 92  M. Adler        added NOMEMCPY do kill use of memcpy().

                                    worked around a Turbo C optimization bug.

    c5   21 Apr 92  M. Adler        added the WSIZE #define to allow reducing

                                    the 32K window size for specialized

                                    applications.

    c6   31 May 92  M. Adler        added some typecasts to eliminate warnings

    c7   27 Jun 92  G. Roelofs      added some more typecasts (444:  MSC bug).

    c8    5 Oct 92  J-l. Gailly     added ifdef'd code to deal with PKZIP bug.

    c9    9 Oct 92  M. Adler        removed a memory error message (~line 416).

    c10  17 Oct 92  G. Roelofs      changed ULONG/UWORD/byte to ulg/ush/uch,

                                    removed old inflate, renamed inflate_entry

                                    to inflate, added Mark's fix to a comment.

   c10.5 14 Dec 92  M. Adler        fix up error messages for incomplete trees.

    c11   2 Jan 93  M. Adler        fixed bug in detection of incomplete

                                    tables, and removed assumption that EOB is

                                    the longest code (bad assumption).

    c12   3 Jan 93  M. Adler        make tables for fixed blocks only once.

    c13   5 Jan 93  M. Adler        allow all zero length codes (pkzip 2.04c

                                    outputs one zero length code for an empty

                                    distance tree).

    c14  12 Mar 93  M. Adler        made inflate.c standalone with the

                                    introduction of inflate.h.

   c14b  16 Jul 93  G. Roelofs      added (unsigned) typecast to w at 470.

   c14c  19 Jul 93  J. Bush         changed v[N_MAX], l[288], ll[28x+3x] arrays

                                    to static for Amiga.

   c14d  13 Aug 93  J-l. Gailly     de-complicatified Mark's c[*p++]++ thing.

   c14e   8 Oct 93  G. Roelofs      changed memset() to memzero().

   c14f  22 Oct 93  G. Roelofs      renamed quietflg to qflag; made Trace()

                                    conditional; added inflate_free().

   c14g  28 Oct 93  G. Roelofs      changed l/(lx+1) macro to pointer (Cray bug)

   c14h   7 Dec 93  C. Ghisler      huft_build() optimizations.

   c14i   9 Jan 94  A. Verheijen    set fixed_t{d,l} to NULL after freeing;

                    G. Roelofs      check NEXTBYTE macro for EOF.

   c14j  23 Jan 94  G. Roelofs      removed Ghisler "optimizations"; ifdef'd

                                    EOF check.

   c14k  27 Feb 94  G. Roelofs      added some typecasts to avoid warnings.

   c14l   9 Apr 94  G. Roelofs      fixed split comments on preprocessor lines

                                    to avoid bug in Encore compiler.

   c14m   7 Jul 94  P. Kienitz      modified to allow assembler version of

                                    inflate_codes() (define ASM_INFLATECODES)

   c14n  22 Jul 94  G. Roelofs      changed fprintf to macro for DLL versions

   c14o  23 Aug 94  C. Spieler      added a newline to a debug statement;

                    G. Roelofs      added another typecast to avoid MSC warning

   c14p   4 Oct 94  G. Roelofs      added (voidp *) cast to free() argument

   c14q  30 Oct 94  G. Roelofs      changed fprintf macro to MESSAGE()

   c14r   1 Nov 94  G. Roelofs      fixed possible redefinition of CHECK_EOF

   c14s   7 May 95  S. Maxwell      OS/2 DLL globals stuff incorporated;

                    P. Kienitz      "fixed" ASM_INFLATECODES macro/prototype

   c14t  18 Aug 95  G. Roelofs      added UZinflate() to use zlib functions;

                                    changed voidp to zvoid; moved huft_build()

                                    and huft_free() to end of file

   c14u   1 Oct 95  G. Roelofs      moved G into definition of MESSAGE macro

   c14v   8 Nov 95  P. Kienitz      changed ASM_INFLATECODES to use a regular

                                    call with __G__ instead of a macro

    c15   3 Aug 96  M. Adler        fixed bomb-bug on random input data (Adobe)

   c15b  24 Aug 96  M. Adler        more fixes for random input data

   c15c  28 Mar 97  G. Roelofs      changed USE_ZLIB fatal exit code from

                                    PK_MEM2 to PK_MEM3

    c16  20 Apr 97  J. Altman       added memzero(v[]) in huft_build()

   c16b  29 Mar 98  C. Spieler      modified DLL code for slide redirection

   c16c  04 Apr 99  C. Spieler      fixed memory leaks when processing gets

                                    stopped because of input data errors

   c16d  05 Jul 99  C. Spieler      take care of FLUSH() return values and

                                    stop processing in case of errors

    c17  31 Dec 00  C. Spieler      added preliminary support for Deflate64

   c17a  04 Feb 01  C. Spieler      complete integration of Deflate64 support

   c17b  16 Feb 02  C. Spieler      changed type of "extra bits" arrays and

                                    corresponding huft_build() parameter e from

                                    ush into uch, to save space

   c17c   9 Mar 02  C. Spieler      fixed NEEDBITS() "read beyond EOF" problem

                                    with CHECK_EOF enabled

   c17d  23 Jul 05  C. Spieler      fixed memory leaks in inflate_dynamic()

                                    when processing invalid compressed literal/

                                    distance table data

   c17e  30 Mar 07  C. Spieler      in inflate_dynamic(), initialize tl and td

                                    to prevent freeing unallocated huft tables

                                    when processing invalid compressed data and

                                    hitting premature EOF, do not reuse td as

                                    temp work ptr during tables decoding

 */

/*

   Inflate deflated (PKZIP's method 8 compressed) data.  The compression

   method searches for as much of the current string of bytes (up to a

   length of 258) in the previous 32K bytes.  If it doesn't find any

   matches (of at least length 3), it codes the next byte.  Otherwise, it

   codes the length of the matched string and its distance backwards from

   the current position.  There is a single Huffman code that codes both

   single bytes (called "literals") and match lengths.  A second Huffman

   code codes the distance information, which follows a length code.  Each

   length or distance code actually represents a base value and a number

   of "extra" (sometimes zero) bits to get to add to the base value.  At

   the end of each deflated block is a special end-of-block (EOB) literal/

   length code.  The decoding process is basically: get a literal/length

   code; if EOB then done; if a literal, emit the decoded byte; if a

   length then get the distance and emit the referred-to bytes from the

   sliding window of previously emitted data.

   There are (currently) three kinds of inflate blocks: stored, fixed, and

   dynamic.  The compressor outputs a chunk of data at a time and decides

   which method to use on a chunk-by-chunk basis.  A chunk might typically

   be 32K to 64K, uncompressed.  If the chunk is uncompressible, then the

   "stored" method is used.  In this case, the bytes are simply stored as

   is, eight bits per byte, with none of the above coding.  The bytes are

   preceded by a count, since there is no longer an EOB code.

   If the data are compressible, then either the fixed or dynamic methods

   are used.  In the dynamic method, the compressed data are preceded by

   an encoding of the literal/length and distance Huffman codes that are

   to be used to decode this block.  The representation is itself Huffman

   coded, and so is preceded by a description of that code.  These code

   descriptions take up a little space, and so for small blocks, there is

   a predefined set of codes, called the fixed codes.  The fixed method is

   used if the block ends up smaller that way (usually for quite small

   chunks); otherwise the dynamic method is used.  In the latter case, the

   codes are customized to the probabilities in the current block and so

   can code it much better than the pre-determined fixed codes can.

   The Huffman codes themselves are decoded using a multi-level table

   lookup, in order to maximize the speed of decoding plus the speed of

   building the decoding tables.  See the comments below that precede the

   lbits and dbits tuning parameters.

   GRR:  return values(?)

           1  incomplete table

           2  bad input

           3  not enough memory

         the following return codes are passed through from FLUSH() errors

           50 (PK_DISK)   "overflow of output space"

           80 (IZ_CTRLC)  "canceled by user's request"

 */

/*

   Notes beyond the 1.93a appnote.txt:

   1. Distance pointers never point before the beginning of the output

      stream.

   2. Distance pointers can point back across blocks, up to 32k away.

   3. There is an implied maximum of 7 bits for the bit length table and

      15 bits for the actual data.

   4. If only one code exists, then it is encoded using one bit.  (Zero

      would be more efficient, but perhaps a little confusing.)  If two

      codes exist, they are coded using one bit each (0 and 1).

   5. There is no way of sending zero distance codes--a dummy must be

      sent if there are none.  (History: a pre 2.0 version of PKZIP would

      store blocks with no distance codes, but this was discovered to be

      too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow

      zero distance codes, which is sent as one code of zero bits in

      length.

   6. There are up to 286 literal/length codes.  Code 256 represents the

      end-of-block.  Note however that the static length tree defines

      288 codes just to fill out the Huffman codes.  Codes 286 and 287

      cannot be used though, since there is no length base or extra bits

      defined for them.  Similarily, there are up to 30 distance codes.

      However, static trees define 32 codes (all 5 bits) to fill out the

      Huffman codes, but the last two had better not show up in the data.

   7. Unzip can check dynamic Huffman blocks for complete code sets.

      The exception is that a single code would not be complete (see #4).

   8. The five bits following the block type is really the number of

      literal codes sent minus 257.

   9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits

      (1+6+6).  Therefore, to output three times the length, you output

      three codes (1+1+1), whereas to output four times the same length,

      you only need two codes (1+3).  Hmm.

  10. In the tree reconstruction algorithm, Code = Code + Increment

      only if BitLength(i) is not zero.  (Pretty obvious.)

  11. Correction: 4 Bits: # of Bit Length codes - 4     (4 - 19)

  12. Note: length code 284 can represent 227-258, but length code 285

      really is 258.  The last length deserves its own, short code

      since it gets used a lot in very redundant files.  The length

      258 is special since 258 - 3 (the min match length) is 255.

  13. The literal/length and distance code bit lengths are read as a

      single stream of lengths.  It is possible (and advantageous) for

      a repeat code (16, 17, or 18) to go across the boundary between

      the two sets of lengths.

  14. The Deflate64 (PKZIP method 9) variant of the compression algorithm

      differs from "classic" deflate in the following 3 aspect:

      a) The size of the sliding history window is expanded to 64 kByte.

      b) The previously unused distance codes #30 and #31 code distances

         from 32769 to 49152 and 49153 to 65536.  Both codes take 14 bits

         of extra data to determine the exact position in their 16 kByte

         range.

      c) The last lit/length code #285 gets a different meaning. Instead

         of coding a fixed maximum match length of 258, it is used as a

         "generic" match length code, capable of coding any length from

         3 (min match length + 0) to 65538 (min match length + 65535).

         This means that the length code #285 takes 16 bits (!) of uncoded

         extra data, added to a fixed min length of 3.

      Changes a) and b) would have been transparent for valid deflated

      data, but change c) requires to switch decoder configurations between

      Deflate and Deflate64 modes.

 */

#define PKZIP_BUG_WORKAROUND    /* PKZIP 1.93a problem--live with it */

/*

    inflate.h must supply the uch slide[WSIZE] array, the zvoid typedef

    (void if (void *) is accepted, else char) and the NEXTBYTE,

    FLUSH() and memzero macros.  If the window size is not 32K, it

    should also define WSIZE.  If INFMOD is defined, it can include

    compiled functions to support the NEXTBYTE and/or FLUSH() macros.

    There are defaults for NEXTBYTE and FLUSH() below for use as

    examples of what those functions need to do.  Normally, you would

    also want FLUSH() to compute a crc on the data.  inflate.h also

    needs to provide these typedefs:

        typedef unsigned char uch;

        typedef unsigned short ush;

        typedef unsigned long ulg;

    This module uses the external functions malloc() and free() (and

    probably memset() or bzero() in the memzero() macro).  Their

    prototypes are normally found in  and .

 */

#define __INFLATE_C     /* identifies this source module */

/* #define DEBUG */

#define INFMOD          /* tell inflate.h to include code to be compiled */

#include "inflate.h"

/* marker for "unused" huft code, and corresponding check macro */

#define INVALID_CODE 99

#define IS_INVALID_CODE(c)  ((c) == INVALID_CODE)

#ifndef WSIZE               /* default is 32K resp. 64K */

#  ifdef USE_DEFLATE64

#    define WSIZE   65536L  /* window size--must be a power of two, and */

#  else                     /*  at least 64K for PKZip's deflate64 method */

#    define WSIZE   0x8000  /* window size--must be a power of two, and */

#  endif                    /*  at least 32K for zip's deflate method */

#endif

/* some buffer counters must be capable of holding 64k for Deflate64 */

#if (defined(USE_DEFLATE64) && defined(INT_16BIT))

#  define UINT_D64 ulg

#else

#  define UINT_D64 unsigned

#endif

#if (defined(DLL) && !defined(NO_SLIDE_REDIR))

#  define wsize G._wsize    /* wsize is a variable */

#else

#  define wsize WSIZE       /* wsize is a constant */

#endif

#ifndef NEXTBYTE        /* default is to simply get a byte from stdin */

#  define NEXTBYTE getchar()

#endif

#ifndef MESSAGE   /* only used twice, for fixed strings--NOT general-purpose */

#  define MESSAGE(str,len,flag)  fprintf(stderr,(char *)(str))

#endif

#ifndef FLUSH           /* default is to simply write the buffer to stdout */

#  define FLUSH(n) \

    (((extent)fwrite(redirSlide, 1, (extent)(n), stdout) == (extent)(n)) ? \

#endif

/* Warning: the fwrite above might not work on 16-bit compilers, since

   0x8000 might be interpreted as -32,768 by the library function.  When

   support for Deflate64 is enabled, the window size is 64K and the

   simple fwrite statement is definitely broken for 16-bit compilers. */

#ifndef Trace

#  ifdef DEBUG

#    define Trace(x) fprintf x

#  else

#    define Trace(x)

#  endif

#endif

/*---------------------------------------------------------------------------*/

#ifdef USE_ZLIB

/* Beginning with zlib version 1.2.0, a new inflate callback interface is

   provided that allows tighter integration of the zlib inflate service

   into unzip's extraction framework.

   The advantages are:

   - uses the windows buffer supplied by the unzip code; this saves one

     copy process between zlib's internal decompression buffer and unzip's

     post-decompression output buffer and improves performance.

   - does not pull in unused checksum code (adler32).

   The preprocessor flag NO_ZLIBCALLBCK can be set to force usage of the

   old zlib 1.1.x interface, for testing purpose.

 */

#ifdef USE_ZLIB_INFLATCB

#  undef USE_ZLIB_INFLATCB

#endif

#if (defined(ZLIB_VERNUM) && ZLIB_VERNUM >= 0x1200 && !defined(NO_ZLIBCALLBCK))

#  define USE_ZLIB_INFLATCB 1

#else

#  define USE_ZLIB_INFLATCB 0

#endif

/* Check for incompatible combinations of zlib and Deflate64 support. */

#if defined(USE_DEFLATE64)

# if !USE_ZLIB_INFLATCB

  #error Deflate64 is incompatible with traditional (pre-1.2.x) zlib interface!

# else

   /* The Deflate64 callback function in the framework of zlib 1.2.x requires

      the inclusion of the unsupported infback9 header file:

    */

#  include "infback9.h"

# endif

#endif /* USE_DEFLATE64 */

#if USE_ZLIB_INFLATCB

static unsigned zlib_inCB OF((void FAR *pG, unsigned char FAR * FAR * pInbuf));

static int zlib_outCB OF((void FAR *pG, unsigned char FAR *outbuf,

                          unsigned outcnt));

static unsigned zlib_inCB(pG, pInbuf)

    void FAR *pG;

    unsigned char FAR * FAR * pInbuf;

{

    *pInbuf = G.inbuf;

    return fillinbuf(__G);

}

static int zlib_outCB(pG, outbuf, outcnt)

    void FAR *pG;

    unsigned char FAR *outbuf;

    unsigned outcnt;

{

#ifdef FUNZIP

    return flush(__G__ (ulg)(outcnt));

#else

    return ((G.mem_mode) ? memflush(__G__ outbuf, (ulg)(outcnt))

                         : flush(__G__ outbuf, (ulg)(outcnt), 0));

#endif

}

#endif /* USE_ZLIB_INFLATCB */

/*

   GRR:  return values for both original inflate() and UZinflate()

           1  incomplete table(?)

           2  bad input

           3  not enough memory

 */

/**************************/

/*  Function UZinflate()  */

/**************************/

int UZinflate(__G__ is_defl64)

    __GDEF

    int is_defl64;

/* decompress an inflated entry using the zlib routines */

{

    int retval = 0;     /* return code: 0 = "no error" */

    int err=Z_OK;

#if USE_ZLIB_INFLATCB

#if (defined(DLL) && !defined(NO_SLIDE_REDIR))

    if (G.redirect_slide)

        wsize = G.redirect_size, redirSlide = G.redirect_buffer;

    else

        wsize = WSIZE, redirSlide = slide;

#endif

    if (!G.inflInit) {

        /* local buffer for efficiency */

        ZCONST char *zlib_RtVersion = zlibVersion();

        /* only need to test this stuff once */

        if ((zlib_RtVersion[0] != ZLIB_VERSION[0]) ||

            (zlib_RtVersion[2] != ZLIB_VERSION[2])) {

            Info(slide, 0x21, ((char *)slide,

              "error:  incompatible zlib version (expected %s, found %s)\n",

              ZLIB_VERSION, zlib_RtVersion));

            return 3;

        } else if (strcmp(zlib_RtVersion, ZLIB_VERSION) != 0)

            Info(slide, 0x21, ((char *)slide,

              "warning:  different zlib version (expected %s, using %s)\n",

              ZLIB_VERSION, zlib_RtVersion));

        G.dstrm.zalloc = (alloc_func)Z_NULL;

        G.dstrm.zfree = (free_func)Z_NULL;

        G.inflInit = 1;

    }

#ifdef USE_DEFLATE64

    if (is_defl64)

    {

        Trace((stderr, "initializing inflate9()\n"));

        err = inflateBack9Init(&G.dstrm, redirSlide);

        if (err == Z_MEM_ERROR)

            return 3;

        else if (err != Z_OK) {

            Trace((stderr, "oops!  (inflateBack9Init() err = %d)\n", err));

            return 2;

        }

        G.dstrm.next_in = G.inptr;

        G.dstrm.avail_in = G.incnt;

        err = inflateBack9(&G.dstrm, zlib_inCB, &G, zlib_outCB, &G);

        if (err != Z_STREAM_END) {

            if (err == Z_DATA_ERROR || err == Z_STREAM_ERROR) {

                Trace((stderr, "oops!  (inflateBack9() err = %d)\n", err));

                retval = 2;

            } else if (err == Z_MEM_ERROR) {

                retval = 3;

            } else if (err == Z_BUF_ERROR) {

                Trace((stderr, "oops!  (inflateBack9() err = %d)\n", err));

                if (G.dstrm.next_in == Z_NULL) {

                    /* input failure */

                    Trace((stderr, "  inflateBack9() input failure\n"));

                    retval = 2;

                } else {

                    /* output write failure */

                    retval = (G.disk_full != 0 ? PK_DISK : IZ_CTRLC);

                }

            } else {

                Trace((stderr, "oops!  (inflateBack9() err = %d)\n", err));

                retval = 2;

            }

        }

        if (G.dstrm.next_in != NULL) {

            G.inptr = (uch *)G.dstrm.next_in;

            G.incnt = G.dstrm.avail_in;

        }

        err = inflateBack9End(&G.dstrm);

        if (err != Z_OK) {

            Trace((stderr, "oops!  (inflateBack9End() err = %d)\n", err));

            if (retval == 0)

                retval = 2;

        }

    }

    else

#endif /* USE_DEFLATE64 */

    {

        /* For the callback interface, inflate initialization has to

           be called before each decompression call.

         */

        {

            unsigned i;

            int windowBits;

            /* windowBits = log2(wsize) */

            for (i = (unsigned)wsize, windowBits = 0;

                 !(i & 1);  i >>= 1, ++windowBits);

            if ((unsigned)windowBits > (unsigned)15)

                windowBits = 15;

            else if (windowBits < 8)

                windowBits = 8;

            Trace((stderr, "initializing inflate()\n"));

            err = inflateBackInit(&G.dstrm, windowBits, redirSlide);

            if (err == Z_MEM_ERROR)

                return 3;

            else if (err != Z_OK) {

                Trace((stderr, "oops!  (inflateBackInit() err = %d)\n", err));

                return 2;

            }

        }

        G.dstrm.next_in = G.inptr;

        G.dstrm.avail_in = G.incnt;

        err = inflateBack(&G.dstrm, zlib_inCB, &G, zlib_outCB, &G);

        if (err != Z_STREAM_END) {

            if (err == Z_DATA_ERROR || err == Z_STREAM_ERROR) {

                Trace((stderr, "oops!  (inflateBack() err = %d)\n", err));

                retval = 2;

            } else if (err == Z_MEM_ERROR) {

                retval = 3;

            } else if (err == Z_BUF_ERROR) {

                Trace((stderr, "oops!  (inflateBack() err = %d)\n", err));

                if (G.dstrm.next_in == Z_NULL) {

                    /* input failure */

                    Trace((stderr, "  inflateBack() input failure\n"));

                    retval = 2;

                } else {

                    /* output write failure */

                    retval = (G.disk_full != 0 ? PK_DISK : IZ_CTRLC);

                }

            } else {

                Trace((stderr, "oops!  (inflateBack() err = %d)\n", err));

                retval = 2;

            }

        }

        if (G.dstrm.next_in != NULL) {

            G.inptr = (uch *)G.dstrm.next_in;

            G.incnt = G.dstrm.avail_in;

        }

        err = inflateBackEnd(&G.dstrm);

        if (err != Z_OK) {

            Trace((stderr, "oops!  (inflateBackEnd() err = %d)\n", err));

            if (retval == 0)

                retval = 2;

        }

    }

#else /* !USE_ZLIB_INFLATCB */

    int repeated_buf_err;

#if (defined(DLL) && !defined(NO_SLIDE_REDIR))

    if (G.redirect_slide)

        wsize = G.redirect_size, redirSlide = G.redirect_buffer;

    else

        wsize = WSIZE, redirSlide = slide;

#endif

    G.dstrm.next_out = redirSlide;

    G.dstrm.avail_out = wsize;

    G.dstrm.next_in = G.inptr;

    G.dstrm.avail_in = G.incnt;

    if (!G.inflInit) {

        unsigned i;

        int windowBits;

        /* local buffer for efficiency */

        ZCONST char *zlib_RtVersion = zlibVersion();

        /* only need to test this stuff once */

        if (zlib_RtVersion[0] != ZLIB_VERSION[0]) {

            Info(slide, 0x21, ((char *)slide,

              "error:  incompatible zlib version (expected %s, found %s)\n",

              ZLIB_VERSION, zlib_RtVersion));

            return 3;

        } else if (strcmp(zlib_RtVersion, ZLIB_VERSION) != 0)

            Info(slide, 0x21, ((char *)slide,

              "warning:  different zlib version (expected %s, using %s)\n",

              ZLIB_VERSION, zlib_RtVersion));

        /* windowBits = log2(wsize) */

        for (i = (unsigned)wsize, windowBits = 0;

             !(i & 1);  i >>= 1, ++windowBits);

        if ((unsigned)windowBits > (unsigned)15)

            windowBits = 15;

        else if (windowBits < 8)

            windowBits = 8;

        G.dstrm.zalloc = (alloc_func)Z_NULL;

        G.dstrm.zfree = (free_func)Z_NULL;

        Trace((stderr, "initializing inflate()\n"));

        err = inflateInit2(&G.dstrm, -windowBits);

        if (err == Z_MEM_ERROR)

            return 3;

        else if (err != Z_OK)

            Trace((stderr, "oops!  (inflateInit2() err = %d)\n", err));

        G.inflInit = 1;

    }

#ifdef FUNZIP

    while (err != Z_STREAM_END) {

#else /* !FUNZIP */

    while (G.csize > 0) {

        Trace((stderr, "first loop:  G.csize = %ld\n", G.csize));

#endif /* ?FUNZIP */

        while (G.dstrm.avail_out > 0) {

            err = inflate(&G.dstrm, Z_PARTIAL_FLUSH);

            if (err == Z_DATA_ERROR) {

                retval = 2; goto uzinflate_cleanup_exit;

            } else if (err == Z_MEM_ERROR) {

                retval = 3; goto uzinflate_cleanup_exit;

            } else if (err != Z_OK && err != Z_STREAM_END)

                Trace((stderr, "oops!  (inflate(first loop) err = %d)\n", err));

#ifdef FUNZIP

            if (err == Z_STREAM_END)    /* "END-of-entry-condition" ? */

#else /* !FUNZIP */

            if (G.csize <= 0L)          /* "END-of-entry-condition" ? */

#endif /* ?FUNZIP */

                break;

            if (G.dstrm.avail_in == 0) {

                if (fillinbuf(__G) == 0) {

                    /* no "END-condition" yet, but no more data */

                    retval = 2; goto uzinflate_cleanup_exit;

                }

                G.dstrm.next_in = G.inptr;

                G.dstrm.avail_in = G.incnt;

            }

            Trace((stderr, "     avail_in = %u\n", G.dstrm.avail_in));

        }

        /* flush slide[] */

        if ((retval = FLUSH(wsize - G.dstrm.avail_out)) != 0)

            goto uzinflate_cleanup_exit;

        Trace((stderr, "inside loop:  flushing %ld bytes (ptr diff = %ld)\n",

          (long)(wsize - G.dstrm.avail_out),

          (long)(G.dstrm.next_out-(Bytef *)redirSlide)));

        G.dstrm.next_out = redirSlide;

        G.dstrm.avail_out = wsize;

    }

    /* no more input, so loop until we have all output */

    Trace((stderr, "beginning final loop:  err = %d\n", err));

    repeated_buf_err = FALSE;

    while (err != Z_STREAM_END) {

        err = inflate(&G.dstrm, Z_PARTIAL_FLUSH);

        if (err == Z_DATA_ERROR) {

            retval = 2; goto uzinflate_cleanup_exit;

        } else if (err == Z_MEM_ERROR) {

            retval = 3; goto uzinflate_cleanup_exit;

        } else if (err == Z_BUF_ERROR) {                /* DEBUG */

#ifdef FUNZIP

            Trace((stderr,

                   "zlib inflate() did not detect stream end\n"));

#else

            Trace((stderr,

                   "zlib inflate() did not detect stream end (%s, %s)\n",

                   G.zipfn, G.filename));

#endif

            if ((!repeated_buf_err) && (G.dstrm.avail_in == 0)) {

                /* when detecting this problem for the first time,

                   try to provide one fake byte beyond "EOF"... */

                G.dstrm.next_in = "";

                G.dstrm.avail_in = 1;

                repeated_buf_err = TRUE;

            } else

                break;

        } else if (err != Z_OK && err != Z_STREAM_END) {

            Trace((stderr, "oops!  (inflate(final loop) err = %d)\n", err));

            DESTROYGLOBALS();

            EXIT(PK_MEM3);

        }

        /* final flush of slide[] */

        if ((retval = FLUSH(wsize - G.dstrm.avail_out)) != 0)

            goto uzinflate_cleanup_exit;

        Trace((stderr, "final loop:  flushing %ld bytes (ptr diff = %ld)\n",

          (long)(wsize - G.dstrm.avail_out),

          (long)(G.dstrm.next_out-(Bytef *)redirSlide)));

        G.dstrm.next_out = redirSlide;

        G.dstrm.avail_out = wsize;

    }

    Trace((stderr, "total in = %lu, total out = %lu\n", G.dstrm.total_in,

      G.dstrm.total_out));

    G.inptr = (uch *)G.dstrm.next_in;

    G.incnt = (G.inbuf + INBUFSIZ) - G.inptr;  /* reset for other routines */

uzinflate_cleanup_exit:

    err = inflateReset(&G.dstrm);

    if (err != Z_OK)

        Trace((stderr, "oops!  (inflateReset() err = %d)\n", err));

#endif /* ?USE_ZLIB_INFLATCB */

    return retval;

}

/*---------------------------------------------------------------------------*/

#else /* !USE_ZLIB */

/* Function prototypes */

#ifndef OF

#  ifdef __STDC__

#    define OF(a) a

#  else

#    define OF(a) ()

#  endif

#endif /* !OF */

int inflate_codes OF((__GPRO__ struct huft *tl, struct huft *td,

                      unsigned bl, unsigned bd));

static int inflate_stored OF((__GPRO));

static int inflate_fixed OF((__GPRO));

static int inflate_dynamic OF((__GPRO));

static int inflate_block OF((__GPRO__ int *e));

/* The inflate algorithm uses a sliding 32K byte window on the uncompressed

   stream to find repeated byte strings.  This is implemented here as a

   circular buffer.  The index is updated simply by incrementing and then

   and'ing with 0x7fff (32K-1). */

/* It is left to other modules to supply the 32K area.  It is assumed

   to be usable as if it were declared "uch slide[32768];" or as just

   "uch *slide;" and then malloc'ed in the latter case.  The definition

   must be in unzip.h, included above. */

/* unsigned wp;  moved to globals.h */     /* current position in slide */

/* Tables for deflate from PKZIP's appnote.txt. */

/* - Order of the bit length code lengths */

static ZCONST unsigned border[] = {

        16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};

/* - Copy lengths for literal codes 257..285 */

#ifdef USE_DEFLATE64

static ZCONST ush cplens64[] = {

        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, 3, 0, 0};

        /* For Deflate64, the code 285 is defined differently. */

#else

#  define cplens32 cplens

#endif

static ZCONST ush cplens32[] = {

        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};

        /* note: see note #13 above about the 258 in this list. */

/* - Extra bits for literal codes 257..285 */

#ifdef USE_DEFLATE64

static ZCONST uch cplext64[] = {

        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,

        3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 16, INVALID_CODE, INVALID_CODE};

#else

#  define cplext32 cplext

#endif

static ZCONST uch cplext32[] = {

        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,

        3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, INVALID_CODE, INVALID_CODE};

/* - Copy offsets for distance codes 0..29 (0..31 for Deflate64) */

static ZCONST ush cpdist[] = {

        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,

#if (defined(USE_DEFLATE64) || defined(PKZIP_BUG_WORKAROUND))

        8193, 12289, 16385, 24577, 32769, 49153};

#else

        8193, 12289, 16385, 24577};

#endif

/* - Extra bits for distance codes 0..29 (0..31 for Deflate64) */

#ifdef USE_DEFLATE64

static ZCONST uch cpdext64[] = {

        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,

        7, 7, 8, 8, 9, 9, 10, 10, 11, 11,

        12, 12, 13, 13, 14, 14};

#else

#  define cpdext32 cpdext

#endif

static ZCONST uch cpdext32[] = {

        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,

        7, 7, 8, 8, 9, 9, 10, 10, 11, 11,

#ifdef PKZIP_BUG_WORKAROUND

        12, 12, 13, 13, INVALID_CODE, INVALID_CODE};

#else

        12, 12, 13, 13};

#endif

#ifdef PKZIP_BUG_WORKAROUND

#  define MAXLITLENS 288

#else

#  define MAXLITLENS 286

#endif

#if (defined(USE_DEFLATE64) || defined(PKZIP_BUG_WORKAROUND))

#  define MAXDISTS 32

#else

#  define MAXDISTS 30

#endif

/* moved to consts.h (included in unzip.c), resp. funzip.c */

#if 0

/* And'ing with mask_bits[n] masks the lower n bits */

ZCONST unsigned near mask_bits[17] = {

    0x0000,

    0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,

    0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff

};

#endif /* 0 */

/* Macros for inflate() bit peeking and grabbing.

   The usage is:

        NEEDBITS(j)

        x = b & mask_bits[j];

        DUMPBITS(j)

   where NEEDBITS makes sure that b has at least j bits in it, and

   DUMPBITS removes the bits from b.  The macros use the variable k

   for the number of bits in b.  Normally, b and k are register

   variables for speed and are initialized at the beginning of a

   routine that uses these macros from a global bit buffer and count.

   In order to not ask for more bits than there are in the compressed

   stream, the Huffman tables are constructed to only ask for just

   enough bits to make up the end-of-block code (value 256).  Then no

   bytes need to be "returned" to the buffer at the end of the last

   block.  See the huft_build() routine.

   Actually, the precautions mentioned above are not sufficient to

   prevent fetches of bits beyound the end of the last block in every

   case. When the last code fetched before the end-of-block code was

   a very short distance code (shorter than "distance-prefetch-bits" -

   "end-of-block code bits"), this last distance code fetch already

   exausts the available data.  To prevent failure of extraction in this

   case, the "read beyond EOF" check delays the raise of the "invalid

   data" error until an actual overflow of "used data" is detected.

   This error condition is only fulfilled when the "number of available

   bits" counter k is found to be negative in the NEEDBITS() macro.

   An alternate fix for that problem adjusts the size of the distance code

   base table so that it does not exceed the length of the end-of-block code

   plus the minimum length of a distance code. This alternate fix can be

   enabled by defining the preprocessor symbol FIX_PAST_EOB_BY_TABLEADJUST.

 */

/* These have been moved to globals.h */

#if 0

ulg bb;                         /* bit buffer */

unsigned bk;                    /* bits in bit buffer */

#endif

#ifndef CHECK_EOF

#  define CHECK_EOF   /* default as of 5.13/5.2 */

#endif

#ifndef CHECK_EOF

#  define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE)<

#else

# ifdef FIX_PAST_EOB_BY_TABLEADJUST

#  define NEEDBITS(n) {while(k<(n)){int c=NEXTBYTE;\

    if(c==EOF){retval=1;goto cleanup_and_exit;}\

    b|=((ulg)c)<

# else

#  define NEEDBITS(n) {while((int)k<(int)(n)){int c=NEXTBYTE;\

    if(c==EOF){if((int)k>=0)break;retval=1;goto cleanup_and_exit;}\

    b|=((ulg)c)<

# endif

#endif

#define DUMPBITS(n) {b>>=(n);k-=(n);}

/*

   Huffman code decoding is performed using a multi-level table lookup.

   The fastest way to decode is to simply build a lookup table whose

   size is determined by the longest code.  However, the time it takes

   to build this table can also be a factor if the data being decoded

   are not very long.  The most common codes are necessarily the

   shortest codes, so those codes dominate the decoding time, and hence

   the speed.  The idea is you can have a shorter table that decodes the

   shorter, more probable codes, and then point to subsidiary tables for

   the longer codes.  The time it costs to decode the longer codes is

   then traded against the time it takes to make longer tables.

   This results of this trade are in the variables lbits and dbits

   below.  lbits is the number of bits the first level table for literal/

   length codes can decode in one step, and dbits is the same thing for

   the distance codes.  Subsequent tables are also less than or equal to

   those sizes.  These values may be adjusted either when all of the

   codes are shorter than that, in which case the longest code length in

   bits is used, or when the shortest code is *longer* than the requested

   table size, in which case the length of the shortest code in bits is

   used.

   There are two different values for the two tables, since they code a

   different number of possibilities each.  The literal/length table

   codes 286 possible values, or in a flat code, a little over eight

   bits.  The distance table codes 30 possible values, or a little less

   than five bits, flat.  The optimum values for speed end up being

   about one bit more than those, so lbits is 8+1 and dbits is 5+1.

   The optimum values may differ though from machine to machine, and

   possibly even between compilers.  Your mileage may vary.

 */

/* bits in base literal/length lookup table */

static ZCONST unsigned lbits = 9;

/* bits in base distance lookup table */

static ZCONST unsigned dbits = 6;

#ifndef ASM_INFLATECODES

int inflate_codes(__G__ tl, td, bl, bd)

     __GDEF

struct huft *tl, *td;   /* literal/length and distance decoder tables */

unsigned bl, bd;        /* number of bits decoded by tl[] and td[] */

/* inflate (decompress) the codes in a deflated (compressed) block.

   Return an error code or zero if it all goes ok. */

{

  register unsigned e;  /* table entry flag/number of extra bits */

  unsigned d;           /* index for copy */

  UINT_D64 n;           /* length for copy (deflate64: might be 64k+2) */

  UINT_D64 w;           /* current window position (deflate64: up to 64k) */

  struct huft *t;       /* pointer to table entry */

  unsigned ml, md;      /* masks for bl and bd bits */

  register ulg b;       /* bit buffer */

  register unsigned k;  /* number of bits in bit buffer */

  int retval = 0;       /* error code returned: initialized to "no error" */

  /* make local copies of globals */

  b = G.bb;                       /* initialize bit buffer */

  k = G.bk;

  w = G.wp;                       /* initialize window position */

  /* inflate the coded data */

  ml = mask_bits[bl];           /* precompute masks for speed */

  md = mask_bits[bd];

  while (1)                     /* do until end of block */

  {

    NEEDBITS(bl)

    t = tl + ((unsigned)b & ml);

    while (1) {

      DUMPBITS(t->b)

      if ((e = t->e) == 32)     /* then it's a literal */

      {

        redirSlide[w++] = (uch)t->v.n;

        if (w == wsize)

        {

          if ((retval = FLUSH(w)) != 0) goto cleanup_and_exit;

          w = 0;

        }

        break;

      }

      if (e < 31)               /* then it's a length */

      {

        /* get length of block to copy */

        NEEDBITS(e)

        n = t->v.n + ((unsigned)b & mask_bits[e]);

        DUMPBITS(e)

        /* decode distance of block to copy */

        NEEDBITS(bd)

        t = td + ((unsigned)b & md);

        while (1) {

          DUMPBITS(t->b)

          if ((e = t->e) < 32)

            break;

          if (IS_INVALID_CODE(e))

            return 1;

          e &= 31;

          NEEDBITS(e)

          t = t->v.t + ((unsigned)b & mask_bits[e]);

        }

        NEEDBITS(e)

        d = (unsigned)w - t->v.n - ((unsigned)b & mask_bits[e]);

        DUMPBITS(e)

        /* do the copy */

        do {

#if (defined(DLL) && !defined(NO_SLIDE_REDIR))

          if (G.redirect_slide) {

            /* &= w/ wsize unnecessary & wrong if redirect */

            if ((UINT_D64)d >= wsize)

              return 1;         /* invalid compressed data */

            e = (unsigned)(wsize - (d > (unsigned)w ? (UINT_D64)d : w));

          }

          else

#endif

            e = (unsigned)(wsize -

                           ((d &= (unsigned)(wsize-1)) > (unsigned)w ?

                            (UINT_D64)d : w));

          if ((UINT_D64)e > n) e = (unsigned)n;

          n -= e;

#ifndef NOMEMCPY

          if ((unsigned)w - d >= e)

          /* (this test assumes unsigned comparison) */

          {

            memcpy(redirSlide + (unsigned)w, redirSlide + d, e);

            w += e;

            d += e;

          }

          else                  /* do it slowly to avoid memcpy() overlap */

#endif /* !NOMEMCPY */

            do {

              redirSlide[w++] = redirSlide[d++];

            } while (--e);

          if (w == wsize)

          {

            if ((retval = FLUSH(w)) != 0) goto cleanup_and_exit;

            w = 0;

          }

        } while (n);

        break;

      }

      if (e == 31)              /* it's the EOB signal */

      {

        /* sorry for this goto, but we have to exit two loops at once */

        goto cleanup_decode;

      }

      if (IS_INVALID_CODE(e))

        return 1;

      e &= 31;

      NEEDBITS(e)

      t = t->v.t + ((unsigned)b & mask_bits[e]);

    }

  }

cleanup_decode:

  /* restore the globals from the locals */

  G.wp = (unsigned)w;             /* restore global window pointer */

  G.bb = b;                       /* restore global bit buffer */

  G.bk = k;

cleanup_and_exit:

  /* done */

  return retval;

}

#endif /* ASM_INFLATECODES */

static int inflate_stored(__G)

     __GDEF

/* "decompress" an inflated type 0 (stored) block. */

{

  UINT_D64 w;           /* current window position (deflate64: up to 64k!) */

  unsigned n;           /* number of bytes in block */

  register ulg b;       /* bit buffer */

  register unsigned k;  /* number of bits in bit buffer */

  int retval = 0;       /* error code returned: initialized to "no error" */

  /* make local copies of globals */

  Trace((stderr, "\nstored block"));

  b = G.bb;                       /* initialize bit buffer */

  k = G.bk;

  w = G.wp;                       /* initialize window position */

  /* go to byte boundary */

  n = k & 7;

  DUMPBITS(n);

  /* get the length and its complement */

  NEEDBITS(16)

  n = ((unsigned)b & 0xffff);

  DUMPBITS(16)

  NEEDBITS(16)

  if (n != (unsigned)((~b) & 0xffff))

    return 1;                   /* error in compressed data */

  DUMPBITS(16)

  /* read and output the compressed data */

  while (n--)

  {

    NEEDBITS(8)

    redirSlide[w++] = (uch)b;

    if (w == wsize)

    {

      if ((retval = FLUSH(w)) != 0) goto cleanup_and_exit;

      w = 0;

    }

    DUMPBITS(8)

  }

  /* restore the globals from the locals */

  G.wp = (unsigned)w;             /* restore global window pointer */

  G.bb = b;                       /* restore global bit buffer */

  G.bk = k;

cleanup_and_exit:

  return retval;

}

/* Globals for literal tables (built once) */

/* Moved to globals.h                      */

#if 0