Subversion Repositories Kolibri OS

Rev

Blame | Last modification | View Log | Download | RSS feed

  1. /*
  2.   Copyright (c) 1990-2008 Info-ZIP.  All rights reserved.
  3.  
  4.   See the accompanying file LICENSE, version 2007-Mar-04 or later
  5.   (the contents of which are also included in unzip.h) for terms of use.
  6.   If, for some reason, all these files are missing, the Info-ZIP license
  7.   also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
  8. */
  9. /* inflate.c -- by Mark Adler
  10.    version c17e, 30 Mar 2007 */
  11.  
  12.  
  13. /* Copyright history:
  14.    - Starting with UnZip 5.41 of 16-April-2000, this source file
  15.      is covered by the Info-Zip LICENSE cited above.
  16.    - Prior versions of this source file, found in UnZip source packages
  17.      up to UnZip 5.40, were put in the public domain.
  18.      The original copyright note by Mark Adler was:
  19.          "You can do whatever you like with this source file,
  20.          though I would prefer that if you modify it and
  21.          redistribute it that you include comments to that effect
  22.          with your name and the date.  Thank you."
  23.  
  24.    History:
  25.    vers    date          who           what
  26.    ----  ---------  --------------  ------------------------------------
  27.     a    ~~ Feb 92  M. Adler        used full (large, one-step) lookup table
  28.     b1   21 Mar 92  M. Adler        first version with partial lookup tables
  29.     b2   21 Mar 92  M. Adler        fixed bug in fixed-code blocks
  30.     b3   22 Mar 92  M. Adler        sped up match copies, cleaned up some
  31.     b4   25 Mar 92  M. Adler        added prototypes; removed window[] (now
  32.                                     is the responsibility of unzip.h--also
  33.                                     changed name to slide[]), so needs diffs
  34.                                     for unzip.c and unzip.h (this allows
  35.                                     compiling in the small model on MSDOS);
  36.                                     fixed cast of q in huft_build();
  37.     b5   26 Mar 92  M. Adler        got rid of unintended macro recursion.
  38.     b6   27 Mar 92  M. Adler        got rid of nextbyte() routine.  fixed
  39.                                     bug in inflate_fixed().
  40.     c1   30 Mar 92  M. Adler        removed lbits, dbits environment variables.
  41.                                     changed BMAX to 16 for explode.  Removed
  42.                                     OUTB usage, and replaced it with flush()--
  43.                                     this was a 20% speed improvement!  Added
  44.                                     an explode.c (to replace unimplod.c) that
  45.                                     uses the huft routines here.  Removed
  46.                                     register union.
  47.     c2    4 Apr 92  M. Adler        fixed bug for file sizes a multiple of 32k.
  48.     c3   10 Apr 92  M. Adler        reduced memory of code tables made by
  49.                                     huft_build significantly (factor of two to
  50.                                     three).
  51.     c4   15 Apr 92  M. Adler        added NOMEMCPY do kill use of memcpy().
  52.                                     worked around a Turbo C optimization bug.
  53.     c5   21 Apr 92  M. Adler        added the WSIZE #define to allow reducing
  54.                                     the 32K window size for specialized
  55.                                     applications.
  56.     c6   31 May 92  M. Adler        added some typecasts to eliminate warnings
  57.     c7   27 Jun 92  G. Roelofs      added some more typecasts (444:  MSC bug).
  58.     c8    5 Oct 92  J-l. Gailly     added ifdef'd code to deal with PKZIP bug.
  59.     c9    9 Oct 92  M. Adler        removed a memory error message (~line 416).
  60.     c10  17 Oct 92  G. Roelofs      changed ULONG/UWORD/byte to ulg/ush/uch,
  61.                                     removed old inflate, renamed inflate_entry
  62.                                     to inflate, added Mark's fix to a comment.
  63.    c10.5 14 Dec 92  M. Adler        fix up error messages for incomplete trees.
  64.     c11   2 Jan 93  M. Adler        fixed bug in detection of incomplete
  65.                                     tables, and removed assumption that EOB is
  66.                                     the longest code (bad assumption).
  67.     c12   3 Jan 93  M. Adler        make tables for fixed blocks only once.
  68.     c13   5 Jan 93  M. Adler        allow all zero length codes (pkzip 2.04c
  69.                                     outputs one zero length code for an empty
  70.                                     distance tree).
  71.     c14  12 Mar 93  M. Adler        made inflate.c standalone with the
  72.                                     introduction of inflate.h.
  73.    c14b  16 Jul 93  G. Roelofs      added (unsigned) typecast to w at 470.
  74.    c14c  19 Jul 93  J. Bush         changed v[N_MAX], l[288], ll[28x+3x] arrays
  75.                                     to static for Amiga.
  76.    c14d  13 Aug 93  J-l. Gailly     de-complicatified Mark's c[*p++]++ thing.
  77.    c14e   8 Oct 93  G. Roelofs      changed memset() to memzero().
  78.    c14f  22 Oct 93  G. Roelofs      renamed quietflg to qflag; made Trace()
  79.                                     conditional; added inflate_free().
  80.    c14g  28 Oct 93  G. Roelofs      changed l/(lx+1) macro to pointer (Cray bug)
  81.    c14h   7 Dec 93  C. Ghisler      huft_build() optimizations.
  82.    c14i   9 Jan 94  A. Verheijen    set fixed_t{d,l} to NULL after freeing;
  83.                     G. Roelofs      check NEXTBYTE macro for EOF.
  84.    c14j  23 Jan 94  G. Roelofs      removed Ghisler "optimizations"; ifdef'd
  85.                                     EOF check.
  86.    c14k  27 Feb 94  G. Roelofs      added some typecasts to avoid warnings.
  87.    c14l   9 Apr 94  G. Roelofs      fixed split comments on preprocessor lines
  88.                                     to avoid bug in Encore compiler.
  89.    c14m   7 Jul 94  P. Kienitz      modified to allow assembler version of
  90.                                     inflate_codes() (define ASM_INFLATECODES)
  91.    c14n  22 Jul 94  G. Roelofs      changed fprintf to macro for DLL versions
  92.    c14o  23 Aug 94  C. Spieler      added a newline to a debug statement;
  93.                     G. Roelofs      added another typecast to avoid MSC warning
  94.    c14p   4 Oct 94  G. Roelofs      added (voidp *) cast to free() argument
  95.    c14q  30 Oct 94  G. Roelofs      changed fprintf macro to MESSAGE()
  96.    c14r   1 Nov 94  G. Roelofs      fixed possible redefinition of CHECK_EOF
  97.    c14s   7 May 95  S. Maxwell      OS/2 DLL globals stuff incorporated;
  98.                     P. Kienitz      "fixed" ASM_INFLATECODES macro/prototype
  99.    c14t  18 Aug 95  G. Roelofs      added UZinflate() to use zlib functions;
  100.                                     changed voidp to zvoid; moved huft_build()
  101.                                     and huft_free() to end of file
  102.    c14u   1 Oct 95  G. Roelofs      moved G into definition of MESSAGE macro
  103.    c14v   8 Nov 95  P. Kienitz      changed ASM_INFLATECODES to use a regular
  104.                                     call with __G__ instead of a macro
  105.     c15   3 Aug 96  M. Adler        fixed bomb-bug on random input data (Adobe)
  106.    c15b  24 Aug 96  M. Adler        more fixes for random input data
  107.    c15c  28 Mar 97  G. Roelofs      changed USE_ZLIB fatal exit code from
  108.                                     PK_MEM2 to PK_MEM3
  109.     c16  20 Apr 97  J. Altman       added memzero(v[]) in huft_build()
  110.    c16b  29 Mar 98  C. Spieler      modified DLL code for slide redirection
  111.    c16c  04 Apr 99  C. Spieler      fixed memory leaks when processing gets
  112.                                     stopped because of input data errors
  113.    c16d  05 Jul 99  C. Spieler      take care of FLUSH() return values and
  114.                                     stop processing in case of errors
  115.     c17  31 Dec 00  C. Spieler      added preliminary support for Deflate64
  116.    c17a  04 Feb 01  C. Spieler      complete integration of Deflate64 support
  117.    c17b  16 Feb 02  C. Spieler      changed type of "extra bits" arrays and
  118.                                     corresponding huft_build() parameter e from
  119.                                     ush into uch, to save space
  120.    c17c   9 Mar 02  C. Spieler      fixed NEEDBITS() "read beyond EOF" problem
  121.                                     with CHECK_EOF enabled
  122.    c17d  23 Jul 05  C. Spieler      fixed memory leaks in inflate_dynamic()
  123.                                     when processing invalid compressed literal/
  124.                                     distance table data
  125.    c17e  30 Mar 07  C. Spieler      in inflate_dynamic(), initialize tl and td
  126.                                     to prevent freeing unallocated huft tables
  127.                                     when processing invalid compressed data and
  128.                                     hitting premature EOF, do not reuse td as
  129.                                     temp work ptr during tables decoding
  130.  */
  131.  
  132.  
  133. /*
  134.    Inflate deflated (PKZIP's method 8 compressed) data.  The compression
  135.    method searches for as much of the current string of bytes (up to a
  136.    length of 258) in the previous 32K bytes.  If it doesn't find any
  137.    matches (of at least length 3), it codes the next byte.  Otherwise, it
  138.    codes the length of the matched string and its distance backwards from
  139.    the current position.  There is a single Huffman code that codes both
  140.    single bytes (called "literals") and match lengths.  A second Huffman
  141.    code codes the distance information, which follows a length code.  Each
  142.    length or distance code actually represents a base value and a number
  143.    of "extra" (sometimes zero) bits to get to add to the base value.  At
  144.    the end of each deflated block is a special end-of-block (EOB) literal/
  145.    length code.  The decoding process is basically: get a literal/length
  146.    code; if EOB then done; if a literal, emit the decoded byte; if a
  147.    length then get the distance and emit the referred-to bytes from the
  148.    sliding window of previously emitted data.
  149.  
  150.    There are (currently) three kinds of inflate blocks: stored, fixed, and
  151.    dynamic.  The compressor outputs a chunk of data at a time and decides
  152.    which method to use on a chunk-by-chunk basis.  A chunk might typically
  153.    be 32K to 64K, uncompressed.  If the chunk is uncompressible, then the
  154.    "stored" method is used.  In this case, the bytes are simply stored as
  155.    is, eight bits per byte, with none of the above coding.  The bytes are
  156.    preceded by a count, since there is no longer an EOB code.
  157.  
  158.    If the data are compressible, then either the fixed or dynamic methods
  159.    are used.  In the dynamic method, the compressed data are preceded by
  160.    an encoding of the literal/length and distance Huffman codes that are
  161.    to be used to decode this block.  The representation is itself Huffman
  162.    coded, and so is preceded by a description of that code.  These code
  163.    descriptions take up a little space, and so for small blocks, there is
  164.    a predefined set of codes, called the fixed codes.  The fixed method is
  165.    used if the block ends up smaller that way (usually for quite small
  166.    chunks); otherwise the dynamic method is used.  In the latter case, the
  167.    codes are customized to the probabilities in the current block and so
  168.    can code it much better than the pre-determined fixed codes can.
  169.  
  170.    The Huffman codes themselves are decoded using a multi-level table
  171.    lookup, in order to maximize the speed of decoding plus the speed of
  172.    building the decoding tables.  See the comments below that precede the
  173.    lbits and dbits tuning parameters.
  174.  
  175.    GRR:  return values(?)
  176.            0  OK
  177.            1  incomplete table
  178.            2  bad input
  179.            3  not enough memory
  180.          the following return codes are passed through from FLUSH() errors
  181.            50 (PK_DISK)   "overflow of output space"
  182.            80 (IZ_CTRLC)  "canceled by user's request"
  183.  */
  184.  
  185.  
  186. /*
  187.    Notes beyond the 1.93a appnote.txt:
  188.  
  189.    1. Distance pointers never point before the beginning of the output
  190.       stream.
  191.    2. Distance pointers can point back across blocks, up to 32k away.
  192.    3. There is an implied maximum of 7 bits for the bit length table and
  193.       15 bits for the actual data.
  194.    4. If only one code exists, then it is encoded using one bit.  (Zero
  195.       would be more efficient, but perhaps a little confusing.)  If two
  196.       codes exist, they are coded using one bit each (0 and 1).
  197.    5. There is no way of sending zero distance codes--a dummy must be
  198.       sent if there are none.  (History: a pre 2.0 version of PKZIP would
  199.       store blocks with no distance codes, but this was discovered to be
  200.       too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow
  201.       zero distance codes, which is sent as one code of zero bits in
  202.       length.
  203.    6. There are up to 286 literal/length codes.  Code 256 represents the
  204.       end-of-block.  Note however that the static length tree defines
  205.       288 codes just to fill out the Huffman codes.  Codes 286 and 287
  206.       cannot be used though, since there is no length base or extra bits
  207.       defined for them.  Similarily, there are up to 30 distance codes.
  208.       However, static trees define 32 codes (all 5 bits) to fill out the
  209.       Huffman codes, but the last two had better not show up in the data.
  210.    7. Unzip can check dynamic Huffman blocks for complete code sets.
  211.       The exception is that a single code would not be complete (see #4).
  212.    8. The five bits following the block type is really the number of
  213.       literal codes sent minus 257.
  214.    9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
  215.       (1+6+6).  Therefore, to output three times the length, you output
  216.       three codes (1+1+1), whereas to output four times the same length,
  217.       you only need two codes (1+3).  Hmm.
  218.   10. In the tree reconstruction algorithm, Code = Code + Increment
  219.       only if BitLength(i) is not zero.  (Pretty obvious.)
  220.   11. Correction: 4 Bits: # of Bit Length codes - 4     (4 - 19)
  221.   12. Note: length code 284 can represent 227-258, but length code 285
  222.       really is 258.  The last length deserves its own, short code
  223.       since it gets used a lot in very redundant files.  The length
  224.       258 is special since 258 - 3 (the min match length) is 255.
  225.   13. The literal/length and distance code bit lengths are read as a
  226.       single stream of lengths.  It is possible (and advantageous) for
  227.       a repeat code (16, 17, or 18) to go across the boundary between
  228.       the two sets of lengths.
  229.   14. The Deflate64 (PKZIP method 9) variant of the compression algorithm
  230.       differs from "classic" deflate in the following 3 aspect:
  231.       a) The size of the sliding history window is expanded to 64 kByte.
  232.       b) The previously unused distance codes #30 and #31 code distances
  233.          from 32769 to 49152 and 49153 to 65536.  Both codes take 14 bits
  234.          of extra data to determine the exact position in their 16 kByte
  235.          range.
  236.       c) The last lit/length code #285 gets a different meaning. Instead
  237.          of coding a fixed maximum match length of 258, it is used as a
  238.          "generic" match length code, capable of coding any length from
  239.          3 (min match length + 0) to 65538 (min match length + 65535).
  240.          This means that the length code #285 takes 16 bits (!) of uncoded
  241.          extra data, added to a fixed min length of 3.
  242.       Changes a) and b) would have been transparent for valid deflated
  243.       data, but change c) requires to switch decoder configurations between
  244.       Deflate and Deflate64 modes.
  245.  */
  246.  
  247.  
  248. #define PKZIP_BUG_WORKAROUND    /* PKZIP 1.93a problem--live with it */
  249.  
  250. /*
  251.     inflate.h must supply the uch slide[WSIZE] array, the zvoid typedef
  252.     (void if (void *) is accepted, else char) and the NEXTBYTE,
  253.     FLUSH() and memzero macros.  If the window size is not 32K, it
  254.     should also define WSIZE.  If INFMOD is defined, it can include
  255.     compiled functions to support the NEXTBYTE and/or FLUSH() macros.
  256.     There are defaults for NEXTBYTE and FLUSH() below for use as
  257.     examples of what those functions need to do.  Normally, you would
  258.     also want FLUSH() to compute a crc on the data.  inflate.h also
  259.     needs to provide these typedefs:
  260.  
  261.         typedef unsigned char uch;
  262.         typedef unsigned short ush;
  263.         typedef unsigned long ulg;
  264.  
  265.     This module uses the external functions malloc() and free() (and
  266.     probably memset() or bzero() in the memzero() macro).  Their
  267.     prototypes are normally found in <string.h> and <stdlib.h>.
  268.  */
  269.  
  270. #define __INFLATE_C     /* identifies this source module */
  271.  
  272. /* #define DEBUG */
  273. #define INFMOD          /* tell inflate.h to include code to be compiled */
  274. #include "inflate.h"
  275.  
  276.  
  277. /* marker for "unused" huft code, and corresponding check macro */
  278. #define INVALID_CODE 99
  279. #define IS_INVALID_CODE(c)  ((c) == INVALID_CODE)
  280.  
  281. #ifndef WSIZE               /* default is 32K resp. 64K */
  282. #  ifdef USE_DEFLATE64
  283. #    define WSIZE   65536L  /* window size--must be a power of two, and */
  284. #  else                     /*  at least 64K for PKZip's deflate64 method */
  285. #    define WSIZE   0x8000  /* window size--must be a power of two, and */
  286. #  endif                    /*  at least 32K for zip's deflate method */
  287. #endif
  288.  
  289. /* some buffer counters must be capable of holding 64k for Deflate64 */
  290. #if (defined(USE_DEFLATE64) && defined(INT_16BIT))
  291. #  define UINT_D64 ulg
  292. #else
  293. #  define UINT_D64 unsigned
  294. #endif
  295.  
  296. #if (defined(DLL) && !defined(NO_SLIDE_REDIR))
  297. #  define wsize G._wsize    /* wsize is a variable */
  298. #else
  299. #  define wsize WSIZE       /* wsize is a constant */
  300. #endif
  301.  
  302.  
  303. #ifndef NEXTBYTE        /* default is to simply get a byte from stdin */
  304. #  define NEXTBYTE getchar()
  305. #endif
  306.  
  307. #ifndef MESSAGE   /* only used twice, for fixed strings--NOT general-purpose */
  308. #  define MESSAGE(str,len,flag)  fprintf(stderr,(char *)(str))
  309. #endif
  310.  
  311. #ifndef FLUSH           /* default is to simply write the buffer to stdout */
  312. #  define FLUSH(n) \
  313.     (((extent)fwrite(redirSlide, 1, (extent)(n), stdout) == (extent)(n)) ? \
  314.      0 : PKDISK)
  315. #endif
  316. /* Warning: the fwrite above might not work on 16-bit compilers, since
  317.    0x8000 might be interpreted as -32,768 by the library function.  When
  318.    support for Deflate64 is enabled, the window size is 64K and the
  319.    simple fwrite statement is definitely broken for 16-bit compilers. */
  320.  
  321. #ifndef Trace
  322. #  ifdef DEBUG
  323. #    define Trace(x) fprintf x
  324. #  else
  325. #    define Trace(x)
  326. #  endif
  327. #endif
  328.  
  329.  
  330. /*---------------------------------------------------------------------------*/
  331. #ifdef USE_ZLIB
  332.  
  333. /* Beginning with zlib version 1.2.0, a new inflate callback interface is
  334.    provided that allows tighter integration of the zlib inflate service
  335.    into unzip's extraction framework.
  336.    The advantages are:
  337.    - uses the windows buffer supplied by the unzip code; this saves one
  338.      copy process between zlib's internal decompression buffer and unzip's
  339.      post-decompression output buffer and improves performance.
  340.    - does not pull in unused checksum code (adler32).
  341.    The preprocessor flag NO_ZLIBCALLBCK can be set to force usage of the
  342.    old zlib 1.1.x interface, for testing purpose.
  343.  */
  344. #ifdef USE_ZLIB_INFLATCB
  345. #  undef USE_ZLIB_INFLATCB
  346. #endif
  347. #if (defined(ZLIB_VERNUM) && ZLIB_VERNUM >= 0x1200 && !defined(NO_ZLIBCALLBCK))
  348. #  define USE_ZLIB_INFLATCB 1
  349. #else
  350. #  define USE_ZLIB_INFLATCB 0
  351. #endif
  352.  
  353. /* Check for incompatible combinations of zlib and Deflate64 support. */
  354. #if defined(USE_DEFLATE64)
  355. # if !USE_ZLIB_INFLATCB
  356.   #error Deflate64 is incompatible with traditional (pre-1.2.x) zlib interface!
  357. # else
  358.    /* The Deflate64 callback function in the framework of zlib 1.2.x requires
  359.       the inclusion of the unsupported infback9 header file:
  360.     */
  361. #  include "infback9.h"
  362. # endif
  363. #endif /* USE_DEFLATE64 */
  364.  
  365.  
  366. #if USE_ZLIB_INFLATCB
  367.  
  368. static unsigned zlib_inCB OF((void FAR *pG, unsigned char FAR * FAR * pInbuf));
  369. static int zlib_outCB OF((void FAR *pG, unsigned char FAR *outbuf,
  370.                           unsigned outcnt));
  371.  
  372. static unsigned zlib_inCB(pG, pInbuf)
  373.     void FAR *pG;
  374.     unsigned char FAR * FAR * pInbuf;
  375. {
  376.     *pInbuf = G.inbuf;
  377.     return fillinbuf(__G);
  378. }
  379.  
  380. static int zlib_outCB(pG, outbuf, outcnt)
  381.     void FAR *pG;
  382.     unsigned char FAR *outbuf;
  383.     unsigned outcnt;
  384. {
  385. #ifdef FUNZIP
  386.     return flush(__G__ (ulg)(outcnt));
  387. #else
  388.     return ((G.mem_mode) ? memflush(__G__ outbuf, (ulg)(outcnt))
  389.                          : flush(__G__ outbuf, (ulg)(outcnt), 0));
  390. #endif
  391. }
  392. #endif /* USE_ZLIB_INFLATCB */
  393.  
  394.  
  395. /*
  396.    GRR:  return values for both original inflate() and UZinflate()
  397.            0  OK
  398.            1  incomplete table(?)
  399.            2  bad input
  400.            3  not enough memory
  401.  */
  402.  
  403. /**************************/
  404. /*  Function UZinflate()  */
  405. /**************************/
  406.  
  407. int UZinflate(__G__ is_defl64)
  408.     __GDEF
  409.     int is_defl64;
  410. /* decompress an inflated entry using the zlib routines */
  411. {
  412.     int retval = 0;     /* return code: 0 = "no error" */
  413.     int err=Z_OK;
  414. #if USE_ZLIB_INFLATCB
  415.  
  416. #if (defined(DLL) && !defined(NO_SLIDE_REDIR))
  417.     if (G.redirect_slide)
  418.         wsize = G.redirect_size, redirSlide = G.redirect_buffer;
  419.     else
  420.         wsize = WSIZE, redirSlide = slide;
  421. #endif
  422.  
  423.     if (!G.inflInit) {
  424.         /* local buffer for efficiency */
  425.         ZCONST char *zlib_RtVersion = zlibVersion();
  426.  
  427.         /* only need to test this stuff once */
  428.         if ((zlib_RtVersion[0] != ZLIB_VERSION[0]) ||
  429.             (zlib_RtVersion[2] != ZLIB_VERSION[2])) {
  430.             Info(slide, 0x21, ((char *)slide,
  431.               "error:  incompatible zlib version (expected %s, found %s)\n",
  432.               ZLIB_VERSION, zlib_RtVersion));
  433.             return 3;
  434.         } else if (strcmp(zlib_RtVersion, ZLIB_VERSION) != 0)
  435.             Info(slide, 0x21, ((char *)slide,
  436.               "warning:  different zlib version (expected %s, using %s)\n",
  437.               ZLIB_VERSION, zlib_RtVersion));
  438.  
  439.         G.dstrm.zalloc = (alloc_func)Z_NULL;
  440.         G.dstrm.zfree = (free_func)Z_NULL;
  441.  
  442.         G.inflInit = 1;
  443.     }
  444.  
  445. #ifdef USE_DEFLATE64
  446.     if (is_defl64)
  447.     {
  448.         Trace((stderr, "initializing inflate9()\n"));
  449.         err = inflateBack9Init(&G.dstrm, redirSlide);
  450.  
  451.         if (err == Z_MEM_ERROR)
  452.             return 3;
  453.         else if (err != Z_OK) {
  454.             Trace((stderr, "oops!  (inflateBack9Init() err = %d)\n", err));
  455.             return 2;
  456.         }
  457.  
  458.         G.dstrm.next_in = G.inptr;
  459.         G.dstrm.avail_in = G.incnt;
  460.  
  461.         err = inflateBack9(&G.dstrm, zlib_inCB, &G, zlib_outCB, &G);
  462.         if (err != Z_STREAM_END) {
  463.             if (err == Z_DATA_ERROR || err == Z_STREAM_ERROR) {
  464.                 Trace((stderr, "oops!  (inflateBack9() err = %d)\n", err));
  465.                 retval = 2;
  466.             } else if (err == Z_MEM_ERROR) {
  467.                 retval = 3;
  468.             } else if (err == Z_BUF_ERROR) {
  469.                 Trace((stderr, "oops!  (inflateBack9() err = %d)\n", err));
  470.                 if (G.dstrm.next_in == Z_NULL) {
  471.                     /* input failure */
  472.                     Trace((stderr, "  inflateBack9() input failure\n"));
  473.                     retval = 2;
  474.                 } else {
  475.                     /* output write failure */
  476.                     retval = (G.disk_full != 0 ? PK_DISK : IZ_CTRLC);
  477.                 }
  478.             } else {
  479.                 Trace((stderr, "oops!  (inflateBack9() err = %d)\n", err));
  480.                 retval = 2;
  481.             }
  482.         }
  483.         if (G.dstrm.next_in != NULL) {
  484.             G.inptr = (uch *)G.dstrm.next_in;
  485.             G.incnt = G.dstrm.avail_in;
  486.         }
  487.  
  488.         err = inflateBack9End(&G.dstrm);
  489.         if (err != Z_OK) {
  490.             Trace((stderr, "oops!  (inflateBack9End() err = %d)\n", err));
  491.             if (retval == 0)
  492.                 retval = 2;
  493.         }
  494.     }
  495.     else
  496. #endif /* USE_DEFLATE64 */
  497.     {
  498.         /* For the callback interface, inflate initialization has to
  499.            be called before each decompression call.
  500.          */
  501.         {
  502.             unsigned i;
  503.             int windowBits;
  504.             /* windowBits = log2(wsize) */
  505.             for (i = (unsigned)wsize, windowBits = 0;
  506.                  !(i & 1);  i >>= 1, ++windowBits);
  507.             if ((unsigned)windowBits > (unsigned)15)
  508.                 windowBits = 15;
  509.             else if (windowBits < 8)
  510.                 windowBits = 8;
  511.  
  512.             Trace((stderr, "initializing inflate()\n"));
  513.             err = inflateBackInit(&G.dstrm, windowBits, redirSlide);
  514.  
  515.             if (err == Z_MEM_ERROR)
  516.                 return 3;
  517.             else if (err != Z_OK) {
  518.                 Trace((stderr, "oops!  (inflateBackInit() err = %d)\n", err));
  519.                 return 2;
  520.             }
  521.         }
  522.  
  523.         G.dstrm.next_in = G.inptr;
  524.         G.dstrm.avail_in = G.incnt;
  525.  
  526.         err = inflateBack(&G.dstrm, zlib_inCB, &G, zlib_outCB, &G);
  527.         if (err != Z_STREAM_END) {
  528.             if (err == Z_DATA_ERROR || err == Z_STREAM_ERROR) {
  529.                 Trace((stderr, "oops!  (inflateBack() err = %d)\n", err));
  530.                 retval = 2;
  531.             } else if (err == Z_MEM_ERROR) {
  532.                 retval = 3;
  533.             } else if (err == Z_BUF_ERROR) {
  534.                 Trace((stderr, "oops!  (inflateBack() err = %d)\n", err));
  535.                 if (G.dstrm.next_in == Z_NULL) {
  536.                     /* input failure */
  537.                     Trace((stderr, "  inflateBack() input failure\n"));
  538.                     retval = 2;
  539.                 } else {
  540.                     /* output write failure */
  541.                     retval = (G.disk_full != 0 ? PK_DISK : IZ_CTRLC);
  542.                 }
  543.             } else {
  544.                 Trace((stderr, "oops!  (inflateBack() err = %d)\n", err));
  545.                 retval = 2;
  546.             }
  547.         }
  548.         if (G.dstrm.next_in != NULL) {
  549.             G.inptr = (uch *)G.dstrm.next_in;
  550.             G.incnt = G.dstrm.avail_in;
  551.         }
  552.  
  553.         err = inflateBackEnd(&G.dstrm);
  554.         if (err != Z_OK) {
  555.             Trace((stderr, "oops!  (inflateBackEnd() err = %d)\n", err));
  556.             if (retval == 0)
  557.                 retval = 2;
  558.         }
  559.     }
  560.  
  561. #else /* !USE_ZLIB_INFLATCB */
  562.     int repeated_buf_err;
  563.  
  564. #if (defined(DLL) && !defined(NO_SLIDE_REDIR))
  565.     if (G.redirect_slide)
  566.         wsize = G.redirect_size, redirSlide = G.redirect_buffer;
  567.     else
  568.         wsize = WSIZE, redirSlide = slide;
  569. #endif
  570.  
  571.     G.dstrm.next_out = redirSlide;
  572.     G.dstrm.avail_out = wsize;
  573.  
  574.     G.dstrm.next_in = G.inptr;
  575.     G.dstrm.avail_in = G.incnt;
  576.  
  577.     if (!G.inflInit) {
  578.         unsigned i;
  579.         int windowBits;
  580.         /* local buffer for efficiency */
  581.         ZCONST char *zlib_RtVersion = zlibVersion();
  582.  
  583.         /* only need to test this stuff once */
  584.         if (zlib_RtVersion[0] != ZLIB_VERSION[0]) {
  585.             Info(slide, 0x21, ((char *)slide,
  586.               "error:  incompatible zlib version (expected %s, found %s)\n",
  587.               ZLIB_VERSION, zlib_RtVersion));
  588.             return 3;
  589.         } else if (strcmp(zlib_RtVersion, ZLIB_VERSION) != 0)
  590.             Info(slide, 0x21, ((char *)slide,
  591.               "warning:  different zlib version (expected %s, using %s)\n",
  592.               ZLIB_VERSION, zlib_RtVersion));
  593.  
  594.         /* windowBits = log2(wsize) */
  595.         for (i = (unsigned)wsize, windowBits = 0;
  596.              !(i & 1);  i >>= 1, ++windowBits);
  597.         if ((unsigned)windowBits > (unsigned)15)
  598.             windowBits = 15;
  599.         else if (windowBits < 8)
  600.             windowBits = 8;
  601.  
  602.         G.dstrm.zalloc = (alloc_func)Z_NULL;
  603.         G.dstrm.zfree = (free_func)Z_NULL;
  604.  
  605.         Trace((stderr, "initializing inflate()\n"));
  606.         err = inflateInit2(&G.dstrm, -windowBits);
  607.  
  608.         if (err == Z_MEM_ERROR)
  609.             return 3;
  610.         else if (err != Z_OK)
  611.             Trace((stderr, "oops!  (inflateInit2() err = %d)\n", err));
  612.         G.inflInit = 1;
  613.     }
  614.  
  615. #ifdef FUNZIP
  616.     while (err != Z_STREAM_END) {
  617. #else /* !FUNZIP */
  618.     while (G.csize > 0) {
  619.         Trace((stderr, "first loop:  G.csize = %ld\n", G.csize));
  620. #endif /* ?FUNZIP */
  621.         while (G.dstrm.avail_out > 0) {
  622.             err = inflate(&G.dstrm, Z_PARTIAL_FLUSH);
  623.  
  624.             if (err == Z_DATA_ERROR) {
  625.                 retval = 2; goto uzinflate_cleanup_exit;
  626.             } else if (err == Z_MEM_ERROR) {
  627.                 retval = 3; goto uzinflate_cleanup_exit;
  628.             } else if (err != Z_OK && err != Z_STREAM_END)
  629.                 Trace((stderr, "oops!  (inflate(first loop) err = %d)\n", err));
  630.  
  631. #ifdef FUNZIP
  632.             if (err == Z_STREAM_END)    /* "END-of-entry-condition" ? */
  633. #else /* !FUNZIP */
  634.             if (G.csize <= 0L)          /* "END-of-entry-condition" ? */
  635. #endif /* ?FUNZIP */
  636.                 break;
  637.  
  638.             if (G.dstrm.avail_in == 0) {
  639.                 if (fillinbuf(__G) == 0) {
  640.                     /* no "END-condition" yet, but no more data */
  641.                     retval = 2; goto uzinflate_cleanup_exit;
  642.                 }
  643.  
  644.                 G.dstrm.next_in = G.inptr;
  645.                 G.dstrm.avail_in = G.incnt;
  646.             }
  647.             Trace((stderr, "     avail_in = %u\n", G.dstrm.avail_in));
  648.         }
  649.         /* flush slide[] */
  650.         if ((retval = FLUSH(wsize - G.dstrm.avail_out)) != 0)
  651.             goto uzinflate_cleanup_exit;
  652.         Trace((stderr, "inside loop:  flushing %ld bytes (ptr diff = %ld)\n",
  653.           (long)(wsize - G.dstrm.avail_out),
  654.           (long)(G.dstrm.next_out-(Bytef *)redirSlide)));
  655.         G.dstrm.next_out = redirSlide;
  656.         G.dstrm.avail_out = wsize;
  657.     }
  658.  
  659.     /* no more input, so loop until we have all output */
  660.     Trace((stderr, "beginning final loop:  err = %d\n", err));
  661.     repeated_buf_err = FALSE;
  662.     while (err != Z_STREAM_END) {
  663.         err = inflate(&G.dstrm, Z_PARTIAL_FLUSH);
  664.         if (err == Z_DATA_ERROR) {
  665.             retval = 2; goto uzinflate_cleanup_exit;
  666.         } else if (err == Z_MEM_ERROR) {
  667.             retval = 3; goto uzinflate_cleanup_exit;
  668.         } else if (err == Z_BUF_ERROR) {                /* DEBUG */
  669. #ifdef FUNZIP
  670.             Trace((stderr,
  671.                    "zlib inflate() did not detect stream end\n"));
  672. #else
  673.             Trace((stderr,
  674.                    "zlib inflate() did not detect stream end (%s, %s)\n",
  675.                    G.zipfn, G.filename));
  676. #endif
  677.             if ((!repeated_buf_err) && (G.dstrm.avail_in == 0)) {
  678.                 /* when detecting this problem for the first time,
  679.                    try to provide one fake byte beyond "EOF"... */
  680.                 G.dstrm.next_in = "";
  681.                 G.dstrm.avail_in = 1;
  682.                 repeated_buf_err = TRUE;
  683.             } else
  684.                 break;
  685.         } else if (err != Z_OK && err != Z_STREAM_END) {
  686.             Trace((stderr, "oops!  (inflate(final loop) err = %d)\n", err));
  687.             DESTROYGLOBALS();
  688.             EXIT(PK_MEM3);
  689.         }
  690.         /* final flush of slide[] */
  691.         if ((retval = FLUSH(wsize - G.dstrm.avail_out)) != 0)
  692.             goto uzinflate_cleanup_exit;
  693.         Trace((stderr, "final loop:  flushing %ld bytes (ptr diff = %ld)\n",
  694.           (long)(wsize - G.dstrm.avail_out),
  695.           (long)(G.dstrm.next_out-(Bytef *)redirSlide)));
  696.         G.dstrm.next_out = redirSlide;
  697.         G.dstrm.avail_out = wsize;
  698.     }
  699.     Trace((stderr, "total in = %lu, total out = %lu\n", G.dstrm.total_in,
  700.       G.dstrm.total_out));
  701.  
  702.     G.inptr = (uch *)G.dstrm.next_in;
  703.     G.incnt = (G.inbuf + INBUFSIZ) - G.inptr;  /* reset for other routines */
  704.  
  705. uzinflate_cleanup_exit:
  706.     err = inflateReset(&G.dstrm);
  707.     if (err != Z_OK)
  708.         Trace((stderr, "oops!  (inflateReset() err = %d)\n", err));
  709.  
  710. #endif /* ?USE_ZLIB_INFLATCB */
  711.     return retval;
  712. }
  713.  
  714.  
  715. /*---------------------------------------------------------------------------*/
  716. #else /* !USE_ZLIB */
  717.  
  718.  
  719. /* Function prototypes */
  720. #ifndef OF
  721. #  ifdef __STDC__
  722. #    define OF(a) a
  723. #  else
  724. #    define OF(a) ()
  725. #  endif
  726. #endif /* !OF */
  727. int inflate_codes OF((__GPRO__ struct huft *tl, struct huft *td,
  728.                       unsigned bl, unsigned bd));
  729. static int inflate_stored OF((__GPRO));
  730. static int inflate_fixed OF((__GPRO));
  731. static int inflate_dynamic OF((__GPRO));
  732. static int inflate_block OF((__GPRO__ int *e));
  733.  
  734.  
  735. /* The inflate algorithm uses a sliding 32K byte window on the uncompressed
  736.    stream to find repeated byte strings.  This is implemented here as a
  737.    circular buffer.  The index is updated simply by incrementing and then
  738.    and'ing with 0x7fff (32K-1). */
  739. /* It is left to other modules to supply the 32K area.  It is assumed
  740.    to be usable as if it were declared "uch slide[32768];" or as just
  741.    "uch *slide;" and then malloc'ed in the latter case.  The definition
  742.    must be in unzip.h, included above. */
  743.  
  744.  
  745. /* unsigned wp;  moved to globals.h */     /* current position in slide */
  746.  
  747. /* Tables for deflate from PKZIP's appnote.txt. */
  748. /* - Order of the bit length code lengths */
  749. static ZCONST unsigned border[] = {
  750.         16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
  751.  
  752. /* - Copy lengths for literal codes 257..285 */
  753. #ifdef USE_DEFLATE64
  754. static ZCONST ush cplens64[] = {
  755.         3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
  756.         35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 3, 0, 0};
  757.         /* For Deflate64, the code 285 is defined differently. */
  758. #else
  759. #  define cplens32 cplens
  760. #endif
  761. static ZCONST ush cplens32[] = {
  762.         3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
  763.         35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
  764.         /* note: see note #13 above about the 258 in this list. */
  765. /* - Extra bits for literal codes 257..285 */
  766. #ifdef USE_DEFLATE64
  767. static ZCONST uch cplext64[] = {
  768.         0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
  769.         3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 16, INVALID_CODE, INVALID_CODE};
  770. #else
  771. #  define cplext32 cplext
  772. #endif
  773. static ZCONST uch cplext32[] = {
  774.         0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
  775.         3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, INVALID_CODE, INVALID_CODE};
  776.  
  777. /* - Copy offsets for distance codes 0..29 (0..31 for Deflate64) */
  778. static ZCONST ush cpdist[] = {
  779.         1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
  780.         257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
  781. #if (defined(USE_DEFLATE64) || defined(PKZIP_BUG_WORKAROUND))
  782.         8193, 12289, 16385, 24577, 32769, 49153};
  783. #else
  784.         8193, 12289, 16385, 24577};
  785. #endif
  786.  
  787. /* - Extra bits for distance codes 0..29 (0..31 for Deflate64) */
  788. #ifdef USE_DEFLATE64
  789. static ZCONST uch cpdext64[] = {
  790.         0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
  791.         7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
  792.         12, 12, 13, 13, 14, 14};
  793. #else
  794. #  define cpdext32 cpdext
  795. #endif
  796. static ZCONST uch cpdext32[] = {
  797.         0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
  798.         7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
  799. #ifdef PKZIP_BUG_WORKAROUND
  800.         12, 12, 13, 13, INVALID_CODE, INVALID_CODE};
  801. #else
  802.         12, 12, 13, 13};
  803. #endif
  804.  
  805. #ifdef PKZIP_BUG_WORKAROUND
  806. #  define MAXLITLENS 288
  807. #else
  808. #  define MAXLITLENS 286
  809. #endif
  810. #if (defined(USE_DEFLATE64) || defined(PKZIP_BUG_WORKAROUND))
  811. #  define MAXDISTS 32
  812. #else
  813. #  define MAXDISTS 30
  814. #endif
  815.  
  816.  
  817. /* moved to consts.h (included in unzip.c), resp. funzip.c */
  818. #if 0
  819. /* And'ing with mask_bits[n] masks the lower n bits */
  820. ZCONST unsigned near mask_bits[17] = {
  821.     0x0000,
  822.     0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
  823.     0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
  824. };
  825. #endif /* 0 */
  826.  
  827.  
  828. /* Macros for inflate() bit peeking and grabbing.
  829.    The usage is:
  830.  
  831.         NEEDBITS(j)
  832.         x = b & mask_bits[j];
  833.         DUMPBITS(j)
  834.  
  835.    where NEEDBITS makes sure that b has at least j bits in it, and
  836.    DUMPBITS removes the bits from b.  The macros use the variable k
  837.    for the number of bits in b.  Normally, b and k are register
  838.    variables for speed and are initialized at the beginning of a
  839.    routine that uses these macros from a global bit buffer and count.
  840.  
  841.    In order to not ask for more bits than there are in the compressed
  842.    stream, the Huffman tables are constructed to only ask for just
  843.    enough bits to make up the end-of-block code (value 256).  Then no
  844.    bytes need to be "returned" to the buffer at the end of the last
  845.    block.  See the huft_build() routine.
  846.  
  847.    Actually, the precautions mentioned above are not sufficient to
  848.    prevent fetches of bits beyound the end of the last block in every
  849.    case. When the last code fetched before the end-of-block code was
  850.    a very short distance code (shorter than "distance-prefetch-bits" -
  851.    "end-of-block code bits"), this last distance code fetch already
  852.    exausts the available data.  To prevent failure of extraction in this
  853.    case, the "read beyond EOF" check delays the raise of the "invalid
  854.    data" error until an actual overflow of "used data" is detected.
  855.    This error condition is only fulfilled when the "number of available
  856.    bits" counter k is found to be negative in the NEEDBITS() macro.
  857.  
  858.    An alternate fix for that problem adjusts the size of the distance code
  859.    base table so that it does not exceed the length of the end-of-block code
  860.    plus the minimum length of a distance code. This alternate fix can be
  861.    enabled by defining the preprocessor symbol FIX_PAST_EOB_BY_TABLEADJUST.
  862.  */
  863.  
  864. /* These have been moved to globals.h */
  865. #if 0
  866. ulg bb;                         /* bit buffer */
  867. unsigned bk;                    /* bits in bit buffer */
  868. #endif
  869.  
  870. #ifndef CHECK_EOF
  871. #  define CHECK_EOF   /* default as of 5.13/5.2 */
  872. #endif
  873.  
  874. #ifndef CHECK_EOF
  875. #  define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE)<<k;k+=8;}}
  876. #else
  877. # ifdef FIX_PAST_EOB_BY_TABLEADJUST
  878. #  define NEEDBITS(n) {while(k<(n)){int c=NEXTBYTE;\
  879.     if(c==EOF){retval=1;goto cleanup_and_exit;}\
  880.     b|=((ulg)c)<<k;k+=8;}}
  881. # else
  882. #  define NEEDBITS(n) {while((int)k<(int)(n)){int c=NEXTBYTE;\
  883.     if(c==EOF){if((int)k>=0)break;retval=1;goto cleanup_and_exit;}\
  884.     b|=((ulg)c)<<k;k+=8;}}
  885. # endif
  886. #endif
  887.  
  888. #define DUMPBITS(n) {b>>=(n);k-=(n);}
  889.  
  890.  
  891. /*
  892.    Huffman code decoding is performed using a multi-level table lookup.
  893.    The fastest way to decode is to simply build a lookup table whose
  894.    size is determined by the longest code.  However, the time it takes
  895.    to build this table can also be a factor if the data being decoded
  896.    are not very long.  The most common codes are necessarily the
  897.    shortest codes, so those codes dominate the decoding time, and hence
  898.    the speed.  The idea is you can have a shorter table that decodes the
  899.    shorter, more probable codes, and then point to subsidiary tables for
  900.    the longer codes.  The time it costs to decode the longer codes is
  901.    then traded against the time it takes to make longer tables.
  902.  
  903.    This results of this trade are in the variables lbits and dbits
  904.    below.  lbits is the number of bits the first level table for literal/
  905.    length codes can decode in one step, and dbits is the same thing for
  906.    the distance codes.  Subsequent tables are also less than or equal to
  907.    those sizes.  These values may be adjusted either when all of the
  908.    codes are shorter than that, in which case the longest code length in
  909.    bits is used, or when the shortest code is *longer* than the requested
  910.    table size, in which case the length of the shortest code in bits is
  911.    used.
  912.  
  913.    There are two different values for the two tables, since they code a
  914.    different number of possibilities each.  The literal/length table
  915.    codes 286 possible values, or in a flat code, a little over eight
  916.    bits.  The distance table codes 30 possible values, or a little less
  917.    than five bits, flat.  The optimum values for speed end up being
  918.    about one bit more than those, so lbits is 8+1 and dbits is 5+1.
  919.    The optimum values may differ though from machine to machine, and
  920.    possibly even between compilers.  Your mileage may vary.
  921.  */
  922.  
  923.  
  924. /* bits in base literal/length lookup table */
  925. static ZCONST unsigned lbits = 9;
  926. /* bits in base distance lookup table */
  927. static ZCONST unsigned dbits = 6;
  928.  
  929.  
  930. #ifndef ASM_INFLATECODES
  931.  
  932. int inflate_codes(__G__ tl, td, bl, bd)
  933.      __GDEF
  934. struct huft *tl, *td;   /* literal/length and distance decoder tables */
  935. unsigned bl, bd;        /* number of bits decoded by tl[] and td[] */
  936. /* inflate (decompress) the codes in a deflated (compressed) block.
  937.    Return an error code or zero if it all goes ok. */
  938. {
  939.   register unsigned e;  /* table entry flag/number of extra bits */
  940.   unsigned d;           /* index for copy */
  941.   UINT_D64 n;           /* length for copy (deflate64: might be 64k+2) */
  942.   UINT_D64 w;           /* current window position (deflate64: up to 64k) */
  943.   struct huft *t;       /* pointer to table entry */
  944.   unsigned ml, md;      /* masks for bl and bd bits */
  945.   register ulg b;       /* bit buffer */
  946.   register unsigned k;  /* number of bits in bit buffer */
  947.   int retval = 0;       /* error code returned: initialized to "no error" */
  948.  
  949.  
  950.   /* make local copies of globals */
  951.   b = G.bb;                       /* initialize bit buffer */
  952.   k = G.bk;
  953.   w = G.wp;                       /* initialize window position */
  954.  
  955.  
  956.   /* inflate the coded data */
  957.   ml = mask_bits[bl];           /* precompute masks for speed */
  958.   md = mask_bits[bd];
  959.   while (1)                     /* do until end of block */
  960.   {
  961.     NEEDBITS(bl)
  962.     t = tl + ((unsigned)b & ml);
  963.     while (1) {
  964.       DUMPBITS(t->b)
  965.  
  966.       if ((e = t->e) == 32)     /* then it's a literal */
  967.       {
  968.         redirSlide[w++] = (uch)t->v.n;
  969.         if (w == wsize)
  970.         {
  971.           if ((retval = FLUSH(w)) != 0) goto cleanup_and_exit;
  972.           w = 0;
  973.         }
  974.         break;
  975.       }
  976.  
  977.       if (e < 31)               /* then it's a length */
  978.       {
  979.         /* get length of block to copy */
  980.         NEEDBITS(e)
  981.         n = t->v.n + ((unsigned)b & mask_bits[e]);
  982.         DUMPBITS(e)
  983.  
  984.         /* decode distance of block to copy */
  985.         NEEDBITS(bd)
  986.         t = td + ((unsigned)b & md);
  987.         while (1) {
  988.           DUMPBITS(t->b)
  989.           if ((e = t->e) < 32)
  990.             break;
  991.           if (IS_INVALID_CODE(e))
  992.             return 1;
  993.           e &= 31;
  994.           NEEDBITS(e)
  995.           t = t->v.t + ((unsigned)b & mask_bits[e]);
  996.         }
  997.         NEEDBITS(e)
  998.         d = (unsigned)w - t->v.n - ((unsigned)b & mask_bits[e]);
  999.         DUMPBITS(e)
  1000.  
  1001.         /* do the copy */
  1002.         do {
  1003. #if (defined(DLL) && !defined(NO_SLIDE_REDIR))
  1004.           if (G.redirect_slide) {
  1005.             /* &= w/ wsize unnecessary & wrong if redirect */
  1006.             if ((UINT_D64)d >= wsize)
  1007.               return 1;         /* invalid compressed data */
  1008.             e = (unsigned)(wsize - (d > (unsigned)w ? (UINT_D64)d : w));
  1009.           }
  1010.           else
  1011. #endif
  1012.             e = (unsigned)(wsize -
  1013.                            ((d &= (unsigned)(wsize-1)) > (unsigned)w ?
  1014.                             (UINT_D64)d : w));
  1015.           if ((UINT_D64)e > n) e = (unsigned)n;
  1016.           n -= e;
  1017. #ifndef NOMEMCPY
  1018.           if ((unsigned)w - d >= e)
  1019.           /* (this test assumes unsigned comparison) */
  1020.           {
  1021.             memcpy(redirSlide + (unsigned)w, redirSlide + d, e);
  1022.             w += e;
  1023.             d += e;
  1024.           }
  1025.           else                  /* do it slowly to avoid memcpy() overlap */
  1026. #endif /* !NOMEMCPY */
  1027.             do {
  1028.               redirSlide[w++] = redirSlide[d++];
  1029.             } while (--e);
  1030.           if (w == wsize)
  1031.           {
  1032.             if ((retval = FLUSH(w)) != 0) goto cleanup_and_exit;
  1033.             w = 0;
  1034.           }
  1035.         } while (n);
  1036.         break;
  1037.       }
  1038.  
  1039.       if (e == 31)              /* it's the EOB signal */
  1040.       {
  1041.         /* sorry for this goto, but we have to exit two loops at once */
  1042.         goto cleanup_decode;
  1043.       }
  1044.  
  1045.       if (IS_INVALID_CODE(e))
  1046.         return 1;
  1047.  
  1048.       e &= 31;
  1049.       NEEDBITS(e)
  1050.       t = t->v.t + ((unsigned)b & mask_bits[e]);
  1051.     }
  1052.   }
  1053. cleanup_decode:
  1054.  
  1055.   /* restore the globals from the locals */
  1056.   G.wp = (unsigned)w;             /* restore global window pointer */
  1057.   G.bb = b;                       /* restore global bit buffer */
  1058.   G.bk = k;
  1059.  
  1060.  
  1061. cleanup_and_exit:
  1062.   /* done */
  1063.   return retval;
  1064. }
  1065.  
  1066. #endif /* ASM_INFLATECODES */
  1067.  
  1068.  
  1069.  
  1070. static int inflate_stored(__G)
  1071.      __GDEF
  1072. /* "decompress" an inflated type 0 (stored) block. */
  1073. {
  1074.   UINT_D64 w;           /* current window position (deflate64: up to 64k!) */
  1075.   unsigned n;           /* number of bytes in block */
  1076.   register ulg b;       /* bit buffer */
  1077.   register unsigned k;  /* number of bits in bit buffer */
  1078.   int retval = 0;       /* error code returned: initialized to "no error" */
  1079.  
  1080.  
  1081.   /* make local copies of globals */
  1082.   Trace((stderr, "\nstored block"));
  1083.   b = G.bb;                       /* initialize bit buffer */
  1084.   k = G.bk;
  1085.   w = G.wp;                       /* initialize window position */
  1086.  
  1087.  
  1088.   /* go to byte boundary */
  1089.   n = k & 7;
  1090.   DUMPBITS(n);
  1091.  
  1092.  
  1093.   /* get the length and its complement */
  1094.   NEEDBITS(16)
  1095.   n = ((unsigned)b & 0xffff);
  1096.   DUMPBITS(16)
  1097.   NEEDBITS(16)
  1098.   if (n != (unsigned)((~b) & 0xffff))
  1099.     return 1;                   /* error in compressed data */
  1100.   DUMPBITS(16)
  1101.  
  1102.  
  1103.   /* read and output the compressed data */
  1104.   while (n--)
  1105.   {
  1106.     NEEDBITS(8)
  1107.     redirSlide[w++] = (uch)b;
  1108.     if (w == wsize)
  1109.     {
  1110.       if ((retval = FLUSH(w)) != 0) goto cleanup_and_exit;
  1111.       w = 0;
  1112.     }
  1113.     DUMPBITS(8)
  1114.   }
  1115.  
  1116.  
  1117.   /* restore the globals from the locals */
  1118.   G.wp = (unsigned)w;             /* restore global window pointer */
  1119.   G.bb = b;                       /* restore global bit buffer */
  1120.   G.bk = k;
  1121.  
  1122. cleanup_and_exit:
  1123.   return retval;
  1124. }
  1125.  
  1126.  
  1127. /* Globals for literal tables (built once) */
  1128. /* Moved to globals.h                      */
  1129. #if 0
  1130. struct huft *fixed_tl = (struct huft *)NULL;
  1131. struct huft *fixed_td;
  1132. int fixed_bl, fixed_bd;
  1133. #endif
  1134.  
  1135. static int inflate_fixed(__G)
  1136.      __GDEF
  1137. /* decompress an inflated type 1 (fixed Huffman codes) block.  We should
  1138.    either replace this with a custom decoder, or at least precompute the
  1139.    Huffman tables. */
  1140. {
  1141.   /* if first time, set up tables for fixed blocks */
  1142.   Trace((stderr, "\nliteral block"));
  1143.   if (G.fixed_tl == (struct huft *)NULL)
  1144.   {
  1145.     int i;                /* temporary variable */
  1146.     unsigned l[288];      /* length list for huft_build */
  1147.  
  1148.     /* literal table */
  1149.     for (i = 0; i < 144; i++)
  1150.       l[i] = 8;
  1151.     for (; i < 256; i++)
  1152.       l[i] = 9;
  1153.     for (; i < 280; i++)
  1154.       l[i] = 7;
  1155.     for (; i < 288; i++)          /* make a complete, but wrong code set */
  1156.       l[i] = 8;
  1157.     G.fixed_bl = 7;
  1158. #ifdef USE_DEFLATE64
  1159.     if ((i = huft_build(__G__ l, 288, 257, G.cplens, G.cplext,
  1160.                         &G.fixed_tl, &G.fixed_bl)) != 0)
  1161. #else
  1162.     if ((i = huft_build(__G__ l, 288, 257, cplens, cplext,
  1163.                         &G.fixed_tl, &G.fixed_bl)) != 0)
  1164. #endif
  1165.     {
  1166.       G.fixed_tl = (struct huft *)NULL;
  1167.       return i;
  1168.     }
  1169.  
  1170.     /* distance table */
  1171.     for (i = 0; i < MAXDISTS; i++)      /* make an incomplete code set */
  1172.       l[i] = 5;
  1173.     G.fixed_bd = 5;
  1174. #ifdef USE_DEFLATE64
  1175.     if ((i = huft_build(__G__ l, MAXDISTS, 0, cpdist, G.cpdext,
  1176.                         &G.fixed_td, &G.fixed_bd)) > 1)
  1177. #else
  1178.     if ((i = huft_build(__G__ l, MAXDISTS, 0, cpdist, cpdext,
  1179.                         &G.fixed_td, &G.fixed_bd)) > 1)
  1180. #endif
  1181.     {
  1182.       huft_free(G.fixed_tl);
  1183.       G.fixed_td = G.fixed_tl = (struct huft *)NULL;
  1184.       return i;
  1185.     }
  1186.   }
  1187.  
  1188.   /* decompress until an end-of-block code */
  1189.   return inflate_codes(__G__ G.fixed_tl, G.fixed_td,
  1190.                              G.fixed_bl, G.fixed_bd);
  1191. }
  1192.  
  1193.  
  1194.  
  1195. static int inflate_dynamic(__G)
  1196.   __GDEF
  1197. /* decompress an inflated type 2 (dynamic Huffman codes) block. */
  1198. {
  1199.   unsigned i;           /* temporary variables */
  1200.   unsigned j;
  1201.   unsigned l;           /* last length */
  1202.   unsigned m;           /* mask for bit lengths table */
  1203.   unsigned n;           /* number of lengths to get */
  1204.   struct huft *tl = (struct huft *)NULL; /* literal/length code table */
  1205.   struct huft *td = (struct huft *)NULL; /* distance code table */
  1206.   struct huft *th;      /* temp huft table pointer used in tables decoding */
  1207.   unsigned bl;          /* lookup bits for tl */
  1208.   unsigned bd;          /* lookup bits for td */
  1209.   unsigned nb;          /* number of bit length codes */
  1210.   unsigned nl;          /* number of literal/length codes */
  1211.   unsigned nd;          /* number of distance codes */
  1212.   unsigned ll[MAXLITLENS+MAXDISTS]; /* lit./length and distance code lengths */
  1213.   register ulg b;       /* bit buffer */
  1214.   register unsigned k;  /* number of bits in bit buffer */
  1215.   int retval = 0;       /* error code returned: initialized to "no error" */
  1216.  
  1217.  
  1218.   /* make local bit buffer */
  1219.   Trace((stderr, "\ndynamic block"));
  1220.   b = G.bb;
  1221.   k = G.bk;
  1222.  
  1223.  
  1224.   /* read in table lengths */
  1225.   NEEDBITS(5)
  1226.   nl = 257 + ((unsigned)b & 0x1f);      /* number of literal/length codes */
  1227.   DUMPBITS(5)
  1228.   NEEDBITS(5)
  1229.   nd = 1 + ((unsigned)b & 0x1f);        /* number of distance codes */
  1230.   DUMPBITS(5)
  1231.   NEEDBITS(4)
  1232.   nb = 4 + ((unsigned)b & 0xf);         /* number of bit length codes */
  1233.   DUMPBITS(4)
  1234.   if (nl > MAXLITLENS || nd > MAXDISTS)
  1235.     return 1;                   /* bad lengths */
  1236.  
  1237.  
  1238.   /* read in bit-length-code lengths */
  1239.   for (j = 0; j < nb; j++)
  1240.   {
  1241.     NEEDBITS(3)
  1242.     ll[border[j]] = (unsigned)b & 7;
  1243.     DUMPBITS(3)
  1244.   }
  1245.   for (; j < 19; j++)
  1246.     ll[border[j]] = 0;
  1247.  
  1248.  
  1249.   /* build decoding table for trees--single level, 7 bit lookup */
  1250.   bl = 7;
  1251.   retval = huft_build(__G__ ll, 19, 19, NULL, NULL, &tl, &bl);
  1252.   if (bl == 0)                  /* no bit lengths */
  1253.     retval = 1;
  1254.   if (retval)
  1255.   {
  1256.     if (retval == 1)
  1257.       huft_free(tl);
  1258.     return retval;              /* incomplete code set */
  1259.   }
  1260.  
  1261.  
  1262.   /* read in literal and distance code lengths */
  1263.   n = nl + nd;
  1264.   m = mask_bits[bl];
  1265.   i = l = 0;
  1266.   while (i < n)
  1267.   {
  1268.     NEEDBITS(bl)
  1269.     j = (th = tl + ((unsigned)b & m))->b;
  1270.     DUMPBITS(j)
  1271.     j = th->v.n;
  1272.     if (j < 16)                 /* length of code in bits (0..15) */
  1273.       ll[i++] = l = j;          /* save last length in l */
  1274.     else if (j == 16)           /* repeat last length 3 to 6 times */
  1275.     {
  1276.       NEEDBITS(2)
  1277.       j = 3 + ((unsigned)b & 3);
  1278.       DUMPBITS(2)
  1279.       if ((unsigned)i + j > n) {
  1280.         huft_free(tl);
  1281.         return 1;
  1282.       }
  1283.       while (j--)
  1284.         ll[i++] = l;
  1285.     }
  1286.     else if (j == 17)           /* 3 to 10 zero length codes */
  1287.     {
  1288.       NEEDBITS(3)
  1289.       j = 3 + ((unsigned)b & 7);
  1290.       DUMPBITS(3)
  1291.       if ((unsigned)i + j > n) {
  1292.         huft_free(tl);
  1293.         return 1;
  1294.       }
  1295.       while (j--)
  1296.         ll[i++] = 0;
  1297.       l = 0;
  1298.     }
  1299.     else                        /* j == 18: 11 to 138 zero length codes */
  1300.     {
  1301.       NEEDBITS(7)
  1302.       j = 11 + ((unsigned)b & 0x7f);
  1303.       DUMPBITS(7)
  1304.       if ((unsigned)i + j > n) {
  1305.         huft_free(tl);
  1306.         return 1;
  1307.       }
  1308.       while (j--)
  1309.         ll[i++] = 0;
  1310.       l = 0;
  1311.     }
  1312.   }
  1313.  
  1314.  
  1315.   /* free decoding table for trees */
  1316.   huft_free(tl);
  1317.  
  1318.  
  1319.   /* restore the global bit buffer */
  1320.   G.bb = b;
  1321.   G.bk = k;
  1322.  
  1323.  
  1324.   /* build the decoding tables for literal/length and distance codes */
  1325.   bl = lbits;
  1326. #ifdef USE_DEFLATE64
  1327.   retval = huft_build(__G__ ll, nl, 257, G.cplens, G.cplext, &tl, &bl);
  1328. #else
  1329.   retval = huft_build(__G__ ll, nl, 257, cplens, cplext, &tl, &bl);
  1330. #endif
  1331.   if (bl == 0)                  /* no literals or lengths */
  1332.     retval = 1;
  1333.   if (retval)
  1334.   {
  1335.     if (retval == 1) {
  1336.       if (!uO.qflag)
  1337.         MESSAGE((uch *)"(incomplete l-tree)  ", 21L, 1);
  1338.       huft_free(tl);
  1339.     }
  1340.     return retval;              /* incomplete code set */
  1341.   }
  1342. #ifdef FIX_PAST_EOB_BY_TABLEADJUST
  1343.   /* Adjust the requested distance base table size so that a distance code
  1344.      fetch never tries to get bits behind an immediatly following end-of-block
  1345.      code. */
  1346.   bd = (dbits <= bl+1 ? dbits : bl+1);
  1347. #else
  1348.   bd = dbits;
  1349. #endif
  1350. #ifdef USE_DEFLATE64
  1351.   retval = huft_build(__G__ ll + nl, nd, 0, cpdist, G.cpdext, &td, &bd);
  1352. #else
  1353.   retval = huft_build(__G__ ll + nl, nd, 0, cpdist, cpdext, &td, &bd);
  1354. #endif
  1355. #ifdef PKZIP_BUG_WORKAROUND
  1356.   if (retval == 1)
  1357.     retval = 0;
  1358. #endif
  1359.   if (bd == 0 && nl > 257)    /* lengths but no distances */
  1360.     retval = 1;
  1361.   if (retval)
  1362.   {
  1363.     if (retval == 1) {
  1364.       if (!uO.qflag)
  1365.         MESSAGE((uch *)"(incomplete d-tree)  ", 21L, 1);
  1366.       huft_free(td);
  1367.     }
  1368.     huft_free(tl);
  1369.     return retval;
  1370.   }
  1371.  
  1372.   /* decompress until an end-of-block code */
  1373.   retval = inflate_codes(__G__ tl, td, bl, bd);
  1374.  
  1375. cleanup_and_exit:
  1376.   /* free the decoding tables, return */
  1377.   if (tl != (struct huft *)NULL)
  1378.     huft_free(tl);
  1379.   if (td != (struct huft *)NULL)
  1380.     huft_free(td);
  1381.   return retval;
  1382. }
  1383.  
  1384.  
  1385.  
  1386. static int inflate_block(__G__ e)
  1387.   __GDEF
  1388.   int *e;               /* last block flag */
  1389. /* decompress an inflated block */
  1390. {
  1391.   unsigned t;           /* block type */
  1392.   register ulg b;       /* bit buffer */
  1393.   register unsigned k;  /* number of bits in bit buffer */
  1394.   int retval = 0;       /* error code returned: initialized to "no error" */
  1395.  
  1396.  
  1397.   /* make local bit buffer */
  1398.   b = G.bb;
  1399.   k = G.bk;
  1400.  
  1401.  
  1402.   /* read in last block bit */
  1403.   NEEDBITS(1)
  1404.   *e = (int)b & 1;
  1405.   DUMPBITS(1)
  1406.  
  1407.  
  1408.   /* read in block type */
  1409.   NEEDBITS(2)
  1410.   t = (unsigned)b & 3;
  1411.   DUMPBITS(2)
  1412.  
  1413.  
  1414.   /* restore the global bit buffer */
  1415.   G.bb = b;
  1416.   G.bk = k;
  1417.  
  1418.  
  1419.   /* inflate that block type */
  1420.   if (t == 2)
  1421.     return inflate_dynamic(__G);
  1422.   if (t == 0)
  1423.     return inflate_stored(__G);
  1424.   if (t == 1)
  1425.     return inflate_fixed(__G);
  1426.  
  1427.  
  1428.   /* bad block type */
  1429.   retval = 2;
  1430.  
  1431. cleanup_and_exit:
  1432.   return retval;
  1433. }
  1434.  
  1435.  
  1436.  
  1437. int inflate(__G__ is_defl64)
  1438.     __GDEF
  1439.     int is_defl64;
  1440. /* decompress an inflated entry */
  1441. {
  1442.   int e;                /* last block flag */
  1443.   int r;                /* result code */
  1444. #ifdef DEBUG
  1445.   unsigned h = 0;       /* maximum struct huft's malloc'ed */
  1446. #endif
  1447.  
  1448. #if (defined(DLL) && !defined(NO_SLIDE_REDIR))
  1449.   if (G.redirect_slide)
  1450.     wsize = G.redirect_size, redirSlide = G.redirect_buffer;
  1451.   else
  1452.     wsize = WSIZE, redirSlide = slide;   /* how they're #defined if !DLL */
  1453. #endif
  1454.  
  1455.   /* initialize window, bit buffer */
  1456.   G.wp = 0;
  1457.   G.bk = 0;
  1458.   G.bb = 0;
  1459.  
  1460. #ifdef USE_DEFLATE64
  1461.   if (is_defl64) {
  1462.     G.cplens = cplens64;
  1463.     G.cplext = cplext64;
  1464.     G.cpdext = cpdext64;
  1465.     G.fixed_tl = G.fixed_tl64;
  1466.     G.fixed_bl = G.fixed_bl64;
  1467.     G.fixed_td = G.fixed_td64;
  1468.     G.fixed_bd = G.fixed_bd64;
  1469.   } else {
  1470.     G.cplens = cplens32;
  1471.     G.cplext = cplext32;
  1472.     G.cpdext = cpdext32;
  1473.     G.fixed_tl = G.fixed_tl32;
  1474.     G.fixed_bl = G.fixed_bl32;
  1475.     G.fixed_td = G.fixed_td32;
  1476.     G.fixed_bd = G.fixed_bd32;
  1477.   }
  1478. #else /* !USE_DEFLATE64 */
  1479.   if (is_defl64) {
  1480.     /* This should not happen unless UnZip is built from object files
  1481.      * compiled with inconsistent option setting.  Handle this by
  1482.      * returning with "bad input" error code.
  1483.      */
  1484.     Trace((stderr, "\nThis inflate() cannot handle Deflate64!\n"));
  1485.     return 2;
  1486.   }
  1487. #endif /* ?USE_DEFLATE64 */
  1488.  
  1489.   /* decompress until the last block */
  1490.   do {
  1491. #ifdef DEBUG
  1492.     G.hufts = 0;
  1493. #endif
  1494.     if ((r = inflate_block(__G__ &e)) != 0)
  1495.       return r;
  1496. #ifdef DEBUG
  1497.     if (G.hufts > h)
  1498.       h = G.hufts;
  1499. #endif
  1500.   } while (!e);
  1501.  
  1502.   Trace((stderr, "\n%u bytes in Huffman tables (%u/entry)\n",
  1503.          h * (unsigned)sizeof(struct huft), (unsigned)sizeof(struct huft)));
  1504.  
  1505. #ifdef USE_DEFLATE64
  1506.   if (is_defl64) {
  1507.     G.fixed_tl64 = G.fixed_tl;
  1508.     G.fixed_bl64 = G.fixed_bl;
  1509.     G.fixed_td64 = G.fixed_td;
  1510.     G.fixed_bd64 = G.fixed_bd;
  1511.   } else {
  1512.     G.fixed_tl32 = G.fixed_tl;
  1513.     G.fixed_bl32 = G.fixed_bl;
  1514.     G.fixed_td32 = G.fixed_td;
  1515.     G.fixed_bd32 = G.fixed_bd;
  1516.   }
  1517. #endif
  1518.  
  1519.   /* flush out redirSlide and return (success, unless final FLUSH failed) */
  1520.   return (FLUSH(G.wp));
  1521. }
  1522.  
  1523.  
  1524.  
  1525. int inflate_free(__G)
  1526.     __GDEF
  1527. {
  1528.   if (G.fixed_tl != (struct huft *)NULL)
  1529.   {
  1530.     huft_free(G.fixed_td);
  1531.     huft_free(G.fixed_tl);
  1532.     G.fixed_td = G.fixed_tl = (struct huft *)NULL;
  1533.   }
  1534.   return 0;
  1535. }
  1536.  
  1537. #endif /* ?USE_ZLIB */
  1538.  
  1539.  
  1540. /*
  1541.  * GRR:  moved huft_build() and huft_free() down here; used by explode()
  1542.  *       and fUnZip regardless of whether USE_ZLIB defined or not
  1543.  */
  1544.  
  1545.  
  1546. /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
  1547. #define BMAX 16         /* maximum bit length of any code (16 for explode) */
  1548. #define N_MAX 288       /* maximum number of codes in any set */
  1549.  
  1550.  
  1551. int huft_build(__G__ b, n, s, d, e, t, m)
  1552.   __GDEF
  1553.   ZCONST unsigned *b;   /* code lengths in bits (all assumed <= BMAX) */
  1554.   unsigned n;           /* number of codes (assumed <= N_MAX) */
  1555.   unsigned s;           /* number of simple-valued codes (0..s-1) */
  1556.   ZCONST ush *d;        /* list of base values for non-simple codes */
  1557.   ZCONST uch *e;        /* list of extra bits for non-simple codes */
  1558.   struct huft **t;      /* result: starting table */
  1559.   unsigned *m;          /* maximum lookup bits, returns actual */
  1560. /* Given a list of code lengths and a maximum table size, make a set of
  1561.    tables to decode that set of codes.  Return zero on success, one if
  1562.    the given code set is incomplete (the tables are still built in this
  1563.    case), two if the input is invalid (all zero length codes or an
  1564.    oversubscribed set of lengths), and three if not enough memory.
  1565.    The code with value 256 is special, and the tables are constructed
  1566.    so that no bits beyond that code are fetched when that code is
  1567.    decoded. */
  1568. {
  1569.   unsigned a;                   /* counter for codes of length k */
  1570.   unsigned c[BMAX+1];           /* bit length count table */
  1571.   unsigned el;                  /* length of EOB code (value 256) */
  1572.   unsigned f;                   /* i repeats in table every f entries */
  1573.   int g;                        /* maximum code length */
  1574.   int h;                        /* table level */
  1575.   register unsigned i;          /* counter, current code */
  1576.   register unsigned j;          /* counter */
  1577.   register int k;               /* number of bits in current code */
  1578.   int lx[BMAX+1];               /* memory for l[-1..BMAX-1] */
  1579.   int *l = lx+1;                /* stack of bits per table */
  1580.   register unsigned *p;         /* pointer into c[], b[], or v[] */
  1581.   register struct huft *q;      /* points to current table */
  1582.   struct huft r;                /* table entry for structure assignment */
  1583.   struct huft *u[BMAX];         /* table stack */
  1584.   unsigned v[N_MAX];            /* values in order of bit length */
  1585.   register int w;               /* bits before this table == (l * h) */
  1586.   unsigned x[BMAX+1];           /* bit offsets, then code stack */
  1587.   unsigned *xp;                 /* pointer into x */
  1588.   int y;                        /* number of dummy codes added */
  1589.   unsigned z;                   /* number of entries in current table */
  1590.  
  1591.  
  1592.   /* Generate counts for each bit length */
  1593.   el = n > 256 ? b[256] : BMAX; /* set length of EOB code, if any */
  1594.   memzero((char *)c, sizeof(c));
  1595.   p = (unsigned *)b;  i = n;
  1596.   do {
  1597.     c[*p]++; p++;               /* assume all entries <= BMAX */
  1598.   } while (--i);
  1599.   if (c[0] == n)                /* null input--all zero length codes */
  1600.   {
  1601.     *t = (struct huft *)NULL;
  1602.     *m = 0;
  1603.     return 0;
  1604.   }
  1605.  
  1606.  
  1607.   /* Find minimum and maximum length, bound *m by those */
  1608.   for (j = 1; j <= BMAX; j++)
  1609.     if (c[j])
  1610.       break;
  1611.   k = j;                        /* minimum code length */
  1612.   if (*m < j)
  1613.     *m = j;
  1614.   for (i = BMAX; i; i--)
  1615.     if (c[i])
  1616.       break;
  1617.   g = i;                        /* maximum code length */
  1618.   if (*m > i)
  1619.     *m = i;
  1620.  
  1621.  
  1622.   /* Adjust last length count to fill out codes, if needed */
  1623.   for (y = 1 << j; j < i; j++, y <<= 1)
  1624.     if ((y -= c[j]) < 0)
  1625.       return 2;                 /* bad input: more codes than bits */
  1626.   if ((y -= c[i]) < 0)
  1627.     return 2;
  1628.   c[i] += y;
  1629.  
  1630.  
  1631.   /* Generate starting offsets into the value table for each length */
  1632.   x[1] = j = 0;
  1633.   p = c + 1;  xp = x + 2;
  1634.   while (--i) {                 /* note that i == g from above */
  1635.     *xp++ = (j += *p++);
  1636.   }
  1637.  
  1638.  
  1639.   /* Make a table of values in order of bit lengths */
  1640.   memzero((char *)v, sizeof(v));
  1641.   p = (unsigned *)b;  i = 0;
  1642.   do {
  1643.     if ((j = *p++) != 0)
  1644.       v[x[j]++] = i;
  1645.   } while (++i < n);
  1646.   n = x[g];                     /* set n to length of v */
  1647.  
  1648.  
  1649.   /* Generate the Huffman codes and for each, make the table entries */
  1650.   x[0] = i = 0;                 /* first Huffman code is zero */
  1651.   p = v;                        /* grab values in bit order */
  1652.   h = -1;                       /* no tables yet--level -1 */
  1653.   w = l[-1] = 0;                /* no bits decoded yet */
  1654.   u[0] = (struct huft *)NULL;   /* just to keep compilers happy */
  1655.   q = (struct huft *)NULL;      /* ditto */
  1656.   z = 0;                        /* ditto */
  1657.  
  1658.   /* go through the bit lengths (k already is bits in shortest code) */
  1659.   for (; k <= g; k++)
  1660.   {
  1661.     a = c[k];
  1662.     while (a--)
  1663.     {
  1664.       /* here i is the Huffman code of length k bits for value *p */
  1665.       /* make tables up to required level */
  1666.       while (k > w + l[h])
  1667.       {
  1668.         w += l[h++];            /* add bits already decoded */
  1669.  
  1670.         /* compute minimum size table less than or equal to *m bits */
  1671.         z = (z = g - w) > *m ? *m : z;                  /* upper limit */
  1672.         if ((f = 1 << (j = k - w)) > a + 1)     /* try a k-w bit table */
  1673.         {                       /* too few codes for k-w bit table */
  1674.           f -= a + 1;           /* deduct codes from patterns left */
  1675.           xp = c + k;
  1676.           while (++j < z)       /* try smaller tables up to z bits */
  1677.           {
  1678.             if ((f <<= 1) <= *++xp)
  1679.               break;            /* enough codes to use up j bits */
  1680.             f -= *xp;           /* else deduct codes from patterns */
  1681.           }
  1682.         }
  1683.         if ((unsigned)w + j > el && (unsigned)w < el)
  1684.           j = el - w;           /* make EOB code end at table */
  1685.         z = 1 << j;             /* table entries for j-bit table */
  1686.         l[h] = j;               /* set table size in stack */
  1687.  
  1688.         /* allocate and link in new table */
  1689.         if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
  1690.             (struct huft *)NULL)
  1691.         {
  1692.           if (h)
  1693.             huft_free(u[0]);
  1694.           return 3;             /* not enough memory */
  1695.         }
  1696. #ifdef DEBUG
  1697.         G.hufts += z + 1;         /* track memory usage */
  1698. #endif
  1699.         *t = q + 1;             /* link to list for huft_free() */
  1700.         *(t = &(q->v.t)) = (struct huft *)NULL;
  1701.         u[h] = ++q;             /* table starts after link */
  1702.  
  1703.         /* connect to last table, if there is one */
  1704.         if (h)
  1705.         {
  1706.           x[h] = i;             /* save pattern for backing up */
  1707.           r.b = (uch)l[h-1];    /* bits to dump before this table */
  1708.           r.e = (uch)(32 + j);  /* bits in this table */
  1709.           r.v.t = q;            /* pointer to this table */
  1710.           j = (i & ((1 << w) - 1)) >> (w - l[h-1]);
  1711.           u[h-1][j] = r;        /* connect to last table */
  1712.         }
  1713.       }
  1714.  
  1715.       /* set up table entry in r */
  1716.       r.b = (uch)(k - w);
  1717.       if (p >= v + n)
  1718.         r.e = INVALID_CODE;     /* out of values--invalid code */
  1719.       else if (*p < s)
  1720.       {
  1721.         r.e = (uch)(*p < 256 ? 32 : 31);  /* 256 is end-of-block code */
  1722.         r.v.n = (ush)*p++;                /* simple code is just the value */
  1723.       }
  1724.       else
  1725.       {
  1726.         r.e = e[*p - s];        /* non-simple--look up in lists */
  1727.         r.v.n = d[*p++ - s];
  1728.       }
  1729.  
  1730.       /* fill code-like entries with r */
  1731.       f = 1 << (k - w);
  1732.       for (j = i >> w; j < z; j += f)
  1733.         q[j] = r;
  1734.  
  1735.       /* backwards increment the k-bit code i */
  1736.       for (j = 1 << (k - 1); i & j; j >>= 1)
  1737.         i ^= j;
  1738.       i ^= j;
  1739.  
  1740.       /* backup over finished tables */
  1741.       while ((i & ((1 << w) - 1)) != x[h])
  1742.         w -= l[--h];            /* don't need to update q */
  1743.     }
  1744.   }
  1745.  
  1746.  
  1747.   /* return actual size of base table */
  1748.   *m = l[0];
  1749.  
  1750.  
  1751.   /* Return true (1) if we were given an incomplete table */
  1752.   return y != 0 && g != 1;
  1753. }
  1754.  
  1755.  
  1756.  
  1757. int huft_free(t)
  1758. struct huft *t;         /* table to free */
  1759. /* Free the malloc'ed tables built by huft_build(), which makes a linked
  1760.    list of the tables it made, with the links in a dummy first entry of
  1761.    each table. */
  1762. {
  1763.   register struct huft *p, *q;
  1764.  
  1765.  
  1766.   /* Go through linked list, freeing from the malloced (t[-1]) address. */
  1767.   p = t;
  1768.   while (p != (struct huft *)NULL)
  1769.   {
  1770.     q = (--p)->v.t;
  1771.     free((zvoid *)p);
  1772.     p = q;
  1773.   }
  1774.   return 0;
  1775. }
  1776.