/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=4 sts=4 sw=4 fenc=utf-8                                :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 1995-2016 Mark Adler                                               │
│ Use of this source code is governed by the BSD-style licenses that can       │
│ be found in the third_party/zlib/LICENSE file.                               │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/str/str.h"
#include "third_party/zlib/chunkcopy.h"
#include "third_party/zlib/inffast.h"
#include "third_party/zlib/inflate.h"
#include "third_party/zlib/inftrees.h"
#include "third_party/zlib/internal.h"
#include "third_party/zlib/zutil.h"

asm(".ident\t\"\\n\\n\
zlib (zlib License)\\n\
Copyright 1995-2017 Jean-loup Gailly and Mark Adler\"");
asm(".include \"libc/disclaimer.inc\"");

/**
 * @fileoverview zlib decompression
 *
 * Change history:
 *
 * 1.2.beta0    24 Nov 2002
 * - First version -- complete rewrite of inflate to simplify code, avoid
 *   creation of window when not needed, minimize use of window when it is
 *   needed, make inffast.c even faster, implement gzip decoding, and to
 *   improve code readability and style over the previous zlib inflate code
 *
 * 1.2.beta1    25 Nov 2002
 * - Use pointers for available input and output checking in inffast.c
 * - Remove input and output counters in inffast.c
 * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
 * - Remove unnecessary second byte pull from length extra in inffast.c
 * - Unroll direct copy to three copies per loop in inffast.c
 *
 * 1.2.beta2    4 Dec 2002
 * - Change external routine names to reduce potential conflicts
 * - Correct filename to inffixed.h for fixed tables in inflate.c
 * - Make hbuf[] unsigned char to match parameter type in inflate.c
 * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
 *   to avoid negation problem on Alphas (64 bit) in inflate.c
 *
 * 1.2.beta3    22 Dec 2002
 * - Add comments on state->bits assertion in inffast.c
 * - Add comments on op field in inftrees.h
 * - Fix bug in reuse of allocated window after inflateReset()
 * - Remove bit fields--back to byte structure for speed
 * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
 * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
 * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
 * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
 * - Use local copies of stream next and avail values, as well as local bit
 *   buffer and bit count in inflate()--for speed when inflate_fast() not used
 *
 * 1.2.beta4    1 Jan 2003
 * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
 * - Move a comment on output buffer sizes from inffast.c to inflate.c
 * - Add comments in inffast.c to introduce the inflate_fast() routine
 * - Rearrange window copies in inflate_fast() for speed and simplification
 * - Unroll last copy for window match in inflate_fast()
 * - Use local copies of window variables in inflate_fast() for speed
 * - Pull out common wnext == 0 case for speed in inflate_fast()
 * - Make op and len in inflate_fast() unsigned for consistency
 * - Add  to lcode and dcode declarations in inflate_fast()
 * - Simplified bad distance check in inflate_fast()
 * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
 *   source file infback.c to provide a call-back interface to inflate for
 *   programs like gzip and unzip -- uses window as output buffer to avoid
 *   window copying
 *
 * 1.2.beta5    1 Jan 2003
 * - Improved inflateBack() interface to allow the caller to provide initial
 *   input in strm.
 * - Fixed stored blocks bug in inflateBack()
 *
 * 1.2.beta6    4 Jan 2003
 * - Added comments in inffast.c on effectiveness of POSTINC
 * - Typecasting all around to reduce compiler warnings
 * - Changed loops from while (1) or do {} while (1) to for (;;), again to
 *   make compilers happy
 * - Changed type of window in inflateBackInit() to unsigned char *
 *
 * 1.2.beta7    27 Jan 2003
 * - Changed many types to unsigned or unsigned short to avoid warnings
 * - Added inflateCopy() function
 *
 * 1.2.0        9 Mar 2003
 * - Changed inflateBack() interface to provide separate opaque descriptors
 *   for the in() and out() functions
 * - Changed inflateBack() argument and in_func typedef to swap the length
 *   and buffer address return values for the input function
 * - Check next_in and next_out for Z_NULL on entry to inflate()
 *
 * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
 */

#ifdef MAKEFIXED
#ifndef BUILDFIXED
#define BUILDFIXED
#endif
#endif

/* permutation of code lengths */
static const unsigned short kZlibDeflateOrder[19] = {
    16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};

static int inflateStateCheck(z_streamp strm);
static void fixedtables(struct InflateState *state);
static int updatewindow(z_streamp strm, const unsigned char *end,
                        unsigned copy);
static unsigned syncsearch(unsigned *have, const unsigned char *buf,
                           unsigned len);
#ifdef BUILDFIXED
void makefixed(void);
#endif

static int inflateStateCheck(z_streamp strm) {
  struct InflateState *state;
  if (strm == Z_NULL || strm->zalloc == (alloc_func)0 ||
      strm->zfree == (free_func)0)
    return 1;
  state = (struct InflateState *)strm->state;
  if (state == Z_NULL || state->strm != strm || state->mode < HEAD ||
      state->mode > SYNC)
    return 1;
  return 0;
}

int inflateResetKeep(z_streamp strm) {
  struct InflateState *state;
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
  strm->total_in = strm->total_out = state->total = 0;
  strm->msg = Z_NULL;
  if (state->wrap) /* to support ill-conceived Java test suite */
    strm->adler = state->wrap & 1;
  state->mode = HEAD;
  state->last = 0;
  state->havedict = 0;
  state->dmax = 32768U;
  state->head = Z_NULL;
  state->hold = 0;
  state->bits = 0;
  state->lencode = state->distcode = state->next = state->codes;
  state->sane = 1;
  state->back = -1;
  Tracev((stderr, "inflate: reset\n"));
  return Z_OK;
}

int inflateReset(z_streamp strm) {
  struct InflateState *state;
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
  state->wsize = 0;
  state->whave = 0;
  state->wnext = 0;
  return inflateResetKeep(strm);
}

int inflateReset2(z_streamp strm, int windowBits) {
  int wrap;
  struct InflateState *state;

  /* get the state */
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;

  /* extract wrap request from windowBits parameter */
  if (windowBits < 0) {
    wrap = 0;
    windowBits = -windowBits;
  } else {
    wrap = (windowBits >> 4) + 5;
#ifdef GUNZIP
    if (windowBits < 48) windowBits &= 15;
#endif
  }

  /* set number of window bits, free window if different */
  if (windowBits && (windowBits < 8 || windowBits > 15)) return Z_STREAM_ERROR;
  if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
    ZFREE(strm, state->window);
    state->window = Z_NULL;
  }

  /* update state and reset the rest of it */
  state->wrap = wrap;
  state->wbits = (unsigned)windowBits;
  return inflateReset(strm);
}

int inflateInit2(z_streamp strm, int windowBits) {
  int ret;
  struct InflateState *state;
  if (strm == Z_NULL) return Z_STREAM_ERROR;
  strm->msg = Z_NULL; /* in case we return an error */
  if (strm->zalloc == (alloc_func)0) {
    strm->zalloc = zcalloc;
    strm->opaque = (voidpf)0;
  }
  if (strm->zfree == (free_func)0) {
    strm->zfree = zcfree;
  }
  state = (struct InflateState *)ZALLOC(strm, 1, sizeof(struct InflateState));
  if (state == Z_NULL) return Z_MEM_ERROR;
  Tracev((stderr, "inflate: allocated\n"));
  strm->state = (struct DeflateState *)state;
  state->strm = strm;
  state->window = Z_NULL;
  state->mode = HEAD; /* to pass state test in inflateReset2() */
  state->check = 1L;  /* 1L is the result of adler32() zero length data */
  ret = inflateReset2(strm, windowBits);
  if (ret != Z_OK) {
    ZFREE(strm, state);
    strm->state = Z_NULL;
  }
  return ret;
}

int inflatePrime(z_streamp strm, int bits, int value) {
  struct InflateState *state;
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
  if (bits < 0) {
    state->hold = 0;
    state->bits = 0;
    return Z_OK;
  }
  if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
  value &= (1L << bits) - 1;
  state->hold += (unsigned)value << state->bits;
  state->bits += (uInt)bits;
  return Z_OK;
}

/**
 * Returns state with length and distance decoding tables and index
 * sizes set to fixed code decoding. Normally this returns fixed tables
 * from inffixed.h. If BUILDFIXED is defined, then instead this routine
 * builds the tables the first time it's called, and returns those
 * tables the first time and thereafter. This reduces the size of the
 * code by about 2K bytes, in exchange for a little execution time.
 * However, BUILDFIXED should not be used for threaded applications,
 * since the rewriting of the tables and virgin may not be thread-safe.
 */
static void fixedtables(struct InflateState *state) {
#ifdef BUILDFIXED
  static int virgin = 1;
  static code *lenfix, *distfix;
  static code fixed[544];

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

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

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

    /* do this just once */
    virgin = 0;
  }
  state->lencode = lenfix;
  state->distcode = distfix;
#else  /* !BUILDFIXED */
  state->lencode = kZlibLenfix;
  state->distcode = kZlibDistfix;
#endif /* BUILDFIXED */
  state->lenbits = 9;
  state->distbits = 5;
}

#ifdef MAKEFIXED
#include "libc/stdio/stdio.h"
/**
 * Writes inffixed.h that is #include'd above. Defining MAKEFIXED also
 * defines BUILDFIXED, so the tables are built on the fly. makefixed()
 * writes those tables to stdout, which would be piped to inffixed.h. A
 * small program can simply call makefixed to do this:
 *
 *   void makefixed(void);
 *
 *   int main(void) {
 *       makefixed();
 *       return 0;
 *   }
 *
 * Then that can be linked with zlib built with MAKEFIXED defined and run:
 *
 *   a.out > inffixed.h
 */
void makefixed(void) {
  unsigned low, size;
  struct InflateState state;
  fixedtables(&state);
  puts("    /* inffixed.h -- table for decoding fixed codes");
  puts("     * Generated automatically by makefixed().");
  puts("     */");
  puts("");
  puts("    /* WARNING: this file should *not* be used by applications.");
  puts("       It is part of the implementation of this library and is");
  puts("       subject to change. Applications should only use zlib.h.");
  puts("     */");
  puts("");
  size = 1U << 9;
  printf("    static const zcode lenfix[%u] = {", size);
  low = 0;
  for (;;) {
    if ((low % 7) == 0) printf("\n        ");
    printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
           state.lencode[low].bits, state.lencode[low].val);
    if (++low == size) break;
    putchar(',');
  }
  puts("\n    };");
  size = 1U << 5;
  printf("\n    static const zcode distfix[%u] = {", size);
  low = 0;
  for (;;) {
    if ((low % 6) == 0) printf("\n        ");
    printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
           state.distcode[low].val);
    if (++low == size) break;
    putchar(',');
  }
  puts("\n    };");
}
#endif /* MAKEFIXED */

/**
 * Updates window with last wsize (normally 32K) bytes written before
 * returning. If window does not exist yet, create it. This is only
 * called when a window is already in use, or when output has been
 * written during this inflate call, but the end of the deflate stream
 * has not been reached yet. It is also called to create a window for
 * dictionary data when a dictionary is loaded.
 *
 * Providing output buffers larger than 32K to inflate() should provide
 * a speed advantage, since only the last 32K of output is copied to the
 * sliding window upon return from inflate(), and since all distances
 * after the first 32K of output will fall in the output data, making
 * match copies simpler and faster. The advantage may be dependent on
 * the size of the processor's data caches.
 */
static int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
  struct InflateState *state;
  unsigned dist;

  state = (struct InflateState *)strm->state;

  /* if it hasn't been done already, allocate space for the window */
  if (state->window == Z_NULL) {
    unsigned wsize = 1U << state->wbits;
    state->window = (unsigned char *)ZALLOC(strm, wsize + CHUNKCOPY_CHUNK_SIZE,
                                            sizeof(unsigned char));
    if (state->window == Z_NULL) return 1;
#ifdef INFLATE_CLEAR_UNUSED_UNDEFINED
    /* Copies from the overflow portion of this buffer are undefined and
       may cause analysis tools to raise a warning if we don't initialize
       it.  However, this undefined data overwrites other undefined data
       and is subsequently either overwritten or left deliberately
       undefined at the end of decode; so there's really no point.
     */
    memset(state->window + wsize, 0, CHUNKCOPY_CHUNK_SIZE);
#endif
  }

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

  /* copy state->wsize or less output bytes into the circular window */
  if (copy >= state->wsize) {
    memcpy(state->window, end - state->wsize, state->wsize);
    state->wnext = 0;
    state->whave = state->wsize;
  } else {
    dist = state->wsize - state->wnext;
    if (dist > copy) dist = copy;
    memcpy(state->window + state->wnext, end - copy, dist);
    copy -= dist;
    if (copy) {
      memcpy(state->window, end - copy, copy);
      state->wnext = copy;
      state->whave = state->wsize;
    } else {
      state->wnext += dist;
      if (state->wnext == state->wsize) state->wnext = 0;
      if (state->whave < state->wsize) state->whave += dist;
    }
  }
  return 0;
}

/* Macros for inflate(): */

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

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

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

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

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

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

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

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

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

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

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

/**
 * inflate() uses a state machine to process as much input data and
 * generate as much output data as possible before returning. The state
 * machine is structured roughly as follows:
 *
 *  for (;;) switch (state) {
 *  ...
 *  case STATEn:
 *      if (not enough input data or output space to make progress)
 *          return;
 *      ... make progress ...
 *      state = STATEm;
 *      break;
 *  ...
 *  }
 *
 * so when inflate() is called again, the same case is attempted again,
 * and if the appropriate resources are provided, the machine proceeds
 * to the next state. The NEEDBITS() macro is usually the way the state
 * evaluates whether it can proceed or should return. NEEDBITS() does
 * the return if the requested bits are not available. The typical use
 * of the BITS macros is:
 *
 *      NEEDBITS(n);
 *      ... do something with BITS(n) ...
 *      DROPBITS(n);
 *
 * where NEEDBITS(n) either returns from inflate() if there isn't enough
 * input left to load n bits into the accumulator, or it continues.
 * BITS(n) gives the low n bits in the accumulator. When done,
 * DROPBITS(n) drops the low n bits off the accumulator. INITBITS()
 * clears the accumulator and sets the number of available bits to zero.
 * BYTEBITS() discards just enough bits to put the accumulator on a byte
 * boundary. After BYTEBITS() and a NEEDBITS(8), then BITS(8) would
 * return the next byte in the stream.
 *
 * NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to
 * return if there is no input available. The decoding of variable
 * length codes uses PULLBYTE() directly in order to pull just enough
 * bytes to decode the next code, and no more.
 *
 * Some states loop until they get enough input, making sure that enough
 * state information is maintained to continue the loop where it left
 * off if NEEDBITS() returns in the loop. For example, want, need, and
 * keep would all have to actually be part of the saved state in case
 * NEEDBITS() returns:
 *
 *  case STATEw:
 *      while (want < need) {
 *          NEEDBITS(n);
 *          keep[want++] = BITS(n);
 *          DROPBITS(n);
 *      }
 *      state = STATEx;
 *  case STATEx:
 *
 * As shown above, if the next state is also the next case, then the
 * break is omitted.
 *
 * A state may also return if there is not enough output space available
 * to complete that state. Those states are copying stored data, writing
 * a literal byte, and copying a matching string.
 *
 * When returning, a "goto inf_leave" is used to update the total
 * counters, update the check value, and determine whether any progress
 * has been made during that inflate() call in order to return the
 * proper return code. Progress is defined as a change in either
 * strm->avail_in or strm->avail_out. When there is a window, goto
 * inf_leave will update the window with the last output written. If a
 * goto inf_leave occurs in the middle of decompression and there is no
 * window currently, goto inf_leave will create one and copy output to
 * the window for the next call of inflate().
 *
 * In this implementation, the flush parameter of inflate() only affects
 * the return code (per zlib.h). inflate() always writes as much as
 * possible to strm->next_out, given the space available and the
 * provided input--the effect documented in zlib.h of Z_SYNC_FLUSH.
 * Furthermore, inflate() always defers the allocation of and copying
 * into a sliding window until necessary, which provides the effect
 * documented in zlib.h for Z_FINISH when the entire input stream
 * available. So the only thing the flush parameter actually does is:
 * when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead
 * it will return Z_BUF_ERROR if it has not reached the end of the
 * stream.
 */
int inflate(z_streamp strm, int flush) {
  struct InflateState *state;
  const unsigned char *next; /* next input */
  unsigned char *put;        /* next output */
  unsigned have, left;       /* available input and output */
  unsigned long hold;        /* bit buffer */
  unsigned bits;             /* bits in bit buffer */
  unsigned in, out;          /* save starting available input and output */
  unsigned copy;             /* number of stored or match bytes to copy */
  unsigned char *from;       /* where to copy match bytes from */
  struct zcode here;         /* current decoding table entry */
  struct zcode last;         /* parent table entry */
  unsigned len;              /* length to copy for repeats, bits to drop */
  int ret;                   /* return code */
#ifdef GUNZIP
  unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
#endif

  if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
      (strm->next_in == Z_NULL && strm->avail_in != 0)) {
    return Z_STREAM_ERROR;
  }
  state = (struct InflateState *)strm->state;
  if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
  LOAD();
  in = have;
  out = left;
  ret = Z_OK;
  for (;;) {
    switch (state->mode) {
      case HEAD:
        if (state->wrap == 0) {
          state->mode = TYPEDO;
          break;
        }
        NEEDBITS(16);
#ifdef GUNZIP
        if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
          if (state->wbits == 0) state->wbits = 15;
          state->check = crc32(0L, Z_NULL, 0);
          CRC2(state->check, hold);
          INITBITS();
          state->mode = FLAGS;
          break;
        }
        state->flags = 0; /* expect zlib header */
        if (state->head != Z_NULL) state->head->done = -1;
        if (!(state->wrap & 1) || /* check if zlib header allowed */
#else
        if (
#endif
            ((BITS(8) << 8) + (hold >> 8)) % 31) {
          strm->msg = (char *)"incorrect header check";
          state->mode = BAD;
          break;
        }
        if (BITS(4) != Z_DEFLATED) {
          strm->msg = (char *)"unknown compression method";
          state->mode = BAD;
          break;
        }
        DROPBITS(4);
        len = BITS(4) + 8;
        if (state->wbits == 0) state->wbits = len;
        if (len > 15 || len > state->wbits) {
          strm->msg = (char *)"invalid window size";
          state->mode = BAD;
          break;
        }
        state->dmax = 1U << len;
        Tracev((stderr, "inflate:   zlib header ok\n"));
        strm->adler = state->check = adler32(0L, Z_NULL, 0);
        state->mode = hold & 0x200 ? DICTID : TYPE;
        INITBITS();
        break;
#ifdef GUNZIP
      case FLAGS:
        NEEDBITS(16);
        state->flags = (int)(hold);
        if ((state->flags & 0xff) != Z_DEFLATED) {
          strm->msg = (char *)"unknown compression method";
          state->mode = BAD;
          break;
        }
        if (state->flags & 0xe000) {
          strm->msg = (char *)"unknown header flags set";
          state->mode = BAD;
          break;
        }
        if (state->head != Z_NULL) state->head->text = (int)((hold >> 8) & 1);
        if ((state->flags & 0x0200) && (state->wrap & 4))
          CRC2(state->check, hold);
        INITBITS();
        state->mode = TIME;
      case TIME:
        NEEDBITS(32);
        if (state->head != Z_NULL) state->head->time = hold;
        if ((state->flags & 0x0200) && (state->wrap & 4))
          CRC4(state->check, hold);
        INITBITS();
        state->mode = OS;
      case OS:
        NEEDBITS(16);
        if (state->head != Z_NULL) {
          state->head->xflags = (int)(hold & 0xff);
          state->head->os = (int)(hold >> 8);
        }
        if ((state->flags & 0x0200) && (state->wrap & 4))
          CRC2(state->check, hold);
        INITBITS();
        state->mode = EXLEN;
      case EXLEN:
        if (state->flags & 0x0400) {
          NEEDBITS(16);
          state->length = (unsigned)(hold);
          if (state->head != Z_NULL) state->head->extra_len = (unsigned)hold;
          if ((state->flags & 0x0200) && (state->wrap & 4))
            CRC2(state->check, hold);
          INITBITS();
        } else if (state->head != Z_NULL)
          state->head->extra = Z_NULL;
        state->mode = EXTRA;
      case EXTRA:
        if (state->flags & 0x0400) {
          copy = state->length;
          if (copy > have) copy = have;
          if (copy) {
            if (state->head != Z_NULL && state->head->extra != Z_NULL) {
              len = state->head->extra_len - state->length;
              memcpy(state->head->extra + len, next,
                     len + copy > state->head->extra_max
                         ? state->head->extra_max - len
                         : copy);
            }
            if ((state->flags & 0x0200) && (state->wrap & 4))
              state->check = crc32(state->check, next, copy);
            have -= copy;
            next += copy;
            state->length -= copy;
          }
          if (state->length) goto inf_leave;
        }
        state->length = 0;
        state->mode = NAME;
      case NAME:
        if (state->flags & 0x0800) {
          if (have == 0) goto inf_leave;
          copy = 0;
          do {
            len = (unsigned)(next[copy++]);
            if (state->head != Z_NULL && state->head->name != Z_NULL &&
                state->length < state->head->name_max)
              state->head->name[state->length++] = (Bytef)len;
          } while (len && copy < have);
          if ((state->flags & 0x0200) && (state->wrap & 4))
            state->check = crc32(state->check, next, copy);
          have -= copy;
          next += copy;
          if (len) goto inf_leave;
        } else if (state->head != Z_NULL)
          state->head->name = Z_NULL;
        state->length = 0;
        state->mode = COMMENT;
      case COMMENT:
        if (state->flags & 0x1000) {
          if (have == 0) goto inf_leave;
          copy = 0;
          do {
            len = (unsigned)(next[copy++]);
            if (state->head != Z_NULL && state->head->comment != Z_NULL &&
                state->length < state->head->comm_max)
              state->head->comment[state->length++] = (Bytef)len;
          } while (len && copy < have);
          if ((state->flags & 0x0200) && (state->wrap & 4))
            state->check = crc32(state->check, next, copy);
          have -= copy;
          next += copy;
          if (len) goto inf_leave;
        } else if (state->head != Z_NULL)
          state->head->comment = Z_NULL;
        state->mode = HCRC;
      case HCRC:
        if (state->flags & 0x0200) {
          NEEDBITS(16);
          if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
            strm->msg = (char *)"header crc mismatch";
            state->mode = BAD;
            break;
          }
          INITBITS();
        }
        if (state->head != Z_NULL) {
          state->head->hcrc = (int)((state->flags >> 9) & 1);
          state->head->done = 1;
        }
        strm->adler = state->check = crc32(0L, Z_NULL, 0);
        state->mode = TYPE;
        break;
#endif
      case DICTID:
        NEEDBITS(32);
        strm->adler = state->check = ZSWAP32(hold);
        INITBITS();
        state->mode = DICT;
      case DICT:
        if (state->havedict == 0) {
          RESTORE();
          return Z_NEED_DICT;
        }
        strm->adler = state->check = adler32(0L, Z_NULL, 0);
        state->mode = TYPE;
      case TYPE:
        if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
      case TYPEDO:
        if (state->last) {
          BYTEBITS();
          state->mode = CHECK;
          break;
        }
        NEEDBITS(3);
        state->last = BITS(1);
        DROPBITS(1);
        switch (BITS(2)) {
          case 0: /* stored block */
            Tracev((stderr, "inflate:     stored block%s\n",
                    state->last ? " (last)" : ""));
            state->mode = STORED;
            break;
          case 1: /* fixed block */
            fixedtables(state);
            Tracev((stderr, "inflate:     fixed codes block%s\n",
                    state->last ? " (last)" : ""));
            state->mode = LEN_; /* decode codes */
            if (flush == Z_TREES) {
              DROPBITS(2);
              goto inf_leave;
            }
            break;
          case 2: /* dynamic block */
            Tracev((stderr, "inflate:     dynamic codes block%s\n",
                    state->last ? " (last)" : ""));
            state->mode = TABLE;
            break;
          case 3:
            strm->msg = (char *)"invalid block type";
            state->mode = BAD;
        }
        DROPBITS(2);
        break;
      case STORED:
        BYTEBITS(); /* go to byte boundary */
        NEEDBITS(32);
        if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
          strm->msg = (char *)"invalid stored block lengths";
          state->mode = BAD;
          break;
        }
        state->length = (unsigned)hold & 0xffff;
        Tracev((stderr, "inflate:       stored length %u\n", state->length));
        INITBITS();
        state->mode = COPY_;
        if (flush == Z_TREES) goto inf_leave;
      case COPY_:
        state->mode = COPY;
      case COPY:
        copy = state->length;
        if (copy) {
          if (copy > have) copy = have;
          if (copy > left) copy = left;
          if (copy == 0) goto inf_leave;
          memcpy(put, next, copy);
          have -= copy;
          next += copy;
          left -= copy;
          put += copy;
          state->length -= copy;
          break;
        }
        Tracev((stderr, "inflate:       stored end\n"));
        state->mode = TYPE;
        break;
      case TABLE:
        NEEDBITS(14);
        state->nlen = BITS(5) + 257;
        DROPBITS(5);
        state->ndist = BITS(5) + 1;
        DROPBITS(5);
        state->ncode = BITS(4) + 4;
        DROPBITS(4);
#ifndef PKZIP_BUG_WORKAROUND
        if (state->nlen > 286 || state->ndist > 30) {
          strm->msg = (char *)"too many length or distance symbols";
          state->mode = BAD;
          break;
        }
#endif
        Tracev((stderr, "inflate:       table sizes ok\n"));
        state->have = 0;
        state->mode = LENLENS;
      case LENLENS:
        while (state->have < state->ncode) {
          NEEDBITS(3);
          state->lens[kZlibDeflateOrder[state->have++]] =
              (unsigned short)BITS(3);
          DROPBITS(3);
        }
        while (state->have < 19) {
          state->lens[kZlibDeflateOrder[state->have++]] = 0;
        }
        state->next = state->codes;
        state->lencode = (const struct zcode *)(state->next);
        state->lenbits = 7;
        ret = inflate_table(CODES, state->lens, 19, &(state->next),
                            &(state->lenbits), state->work);
        if (ret) {
          strm->msg = (char *)"invalid code lengths set";
          state->mode = BAD;
          break;
        }
        Tracev((stderr, "inflate:       code lengths ok\n"));
        state->have = 0;
        state->mode = CODELENS;
      case CODELENS:
        while (state->have < state->nlen + state->ndist) {
          for (;;) {
            here = state->lencode[BITS(state->lenbits)];
            if ((unsigned)(here.bits) <= bits) break;
            PULLBYTE();
          }
          if (here.val < 16) {
            DROPBITS(here.bits);
            state->lens[state->have++] = here.val;
          } else {
            if (here.val == 16) {
              NEEDBITS(here.bits + 2);
              DROPBITS(here.bits);
              if (state->have == 0) {
                strm->msg = (char *)"invalid bit length repeat";
                state->mode = BAD;
                break;
              }
              len = state->lens[state->have - 1];
              copy = 3 + BITS(2);
              DROPBITS(2);
            } else if (here.val == 17) {
              NEEDBITS(here.bits + 3);
              DROPBITS(here.bits);
              len = 0;
              copy = 3 + BITS(3);
              DROPBITS(3);
            } else {
              NEEDBITS(here.bits + 7);
              DROPBITS(here.bits);
              len = 0;
              copy = 11 + BITS(7);
              DROPBITS(7);
            }
            if (state->have + copy > state->nlen + state->ndist) {
              strm->msg = (char *)"invalid bit length repeat";
              state->mode = BAD;
              break;
            }
            while (copy--) state->lens[state->have++] = (unsigned short)len;
          }
        }

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

        /* check for end-of-block code (better have one) */
        if (state->lens[256] == 0) {
          strm->msg = (char *)"invalid code -- missing end-of-block";
          state->mode = BAD;
          break;
        }

        /* build code tables -- note: do not change the lenbits or distbits
           values here (9 and 6) without reading the comments in inftrees.h
           concerning the ENOUGH constants, which depend on those values */
        state->next = state->codes;
        state->lencode = (const struct zcode *)(state->next);
        state->lenbits = 9;
        ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
                            &(state->lenbits), state->work);
        if (ret) {
          strm->msg = (char *)"invalid literal/lengths set";
          state->mode = BAD;
          break;
        }
        state->distcode = (const struct zcode *)(state->next);
        state->distbits = 6;
        ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
                            &(state->next), &(state->distbits), state->work);
        if (ret) {
          strm->msg = (char *)"invalid distances set";
          state->mode = BAD;
          break;
        }
        Tracev((stderr, "inflate:       codes ok\n"));
        state->mode = LEN_;
        if (flush == Z_TREES) goto inf_leave;
      case LEN_:
        state->mode = LEN;
      case LEN:
        if (have >= INFLATE_FAST_MIN_INPUT && left >= INFLATE_FAST_MIN_OUTPUT) {
          RESTORE();
          inflate_fast_chunk(strm, out);
          LOAD();
          if (state->mode == TYPE) state->back = -1;
          break;
        }
        state->back = 0;
        for (;;) {
          here = state->lencode[BITS(state->lenbits)];
          if ((unsigned)(here.bits) <= bits) break;
          PULLBYTE();
        }
        if (here.op && (here.op & 0xf0) == 0) {
          last = here;
          for (;;) {
            here = state->lencode[last.val +
                                  (BITS(last.bits + last.op) >> last.bits)];
            if ((unsigned)(last.bits + here.bits) <= bits) break;
            PULLBYTE();
          }
          DROPBITS(last.bits);
          state->back += last.bits;
        }
        DROPBITS(here.bits);
        state->back += here.bits;
        state->length = (unsigned)here.val;
        if ((int)(here.op) == 0) {
          Tracevv((stderr,
                   here.val >= 0x20 && here.val < 0x7f
                       ? "inflate:         literal '%c'\n"
                       : "inflate:         literal 0x%02x\n",
                   here.val));
          state->mode = LIT;
          break;
        }
        if (here.op & 32) {
          Tracevv((stderr, "inflate:         end of block\n"));
          state->back = -1;
          state->mode = TYPE;
          break;
        }
        if (here.op & 64) {
          strm->msg = (char *)"invalid literal/length code";
          state->mode = BAD;
          break;
        }
        state->extra = (unsigned)(here.op) & 15;
        state->mode = LENEXT;
      case LENEXT:
        if (state->extra) {
          NEEDBITS(state->extra);
          state->length += BITS(state->extra);
          DROPBITS(state->extra);
          state->back += state->extra;
        }
        Tracevv((stderr, "inflate:         length %u\n", state->length));
        state->was = state->length;
        state->mode = DIST;
      case DIST:
        for (;;) {
          here = state->distcode[BITS(state->distbits)];
          if ((unsigned)(here.bits) <= bits) break;
          PULLBYTE();
        }
        if ((here.op & 0xf0) == 0) {
          last = here;
          for (;;) {
            here = state->distcode[last.val +
                                   (BITS(last.bits + last.op) >> last.bits)];
            if ((unsigned)(last.bits + here.bits) <= bits) break;
            PULLBYTE();
          }
          DROPBITS(last.bits);
          state->back += last.bits;
        }
        DROPBITS(here.bits);
        state->back += here.bits;
        if (here.op & 64) {
          strm->msg = (char *)"invalid distance code";
          state->mode = BAD;
          break;
        }
        state->offset = (unsigned)here.val;
        state->extra = (unsigned)(here.op) & 15;
        state->mode = DISTEXT;
      case DISTEXT:
        if (state->extra) {
          NEEDBITS(state->extra);
          state->offset += BITS(state->extra);
          DROPBITS(state->extra);
          state->back += state->extra;
        }
#ifdef INFLATE_STRICT
        if (state->offset > state->dmax) {
          strm->msg = (char *)"invalid distance too far back";
          state->mode = BAD;
          break;
        }
#endif
        Tracevv((stderr, "inflate:         distance %u\n", state->offset));
        state->mode = MATCH;
      case MATCH:
        if (left == 0) goto inf_leave;
        copy = out - left;
        if (state->offset > copy) { /* copy from window */
          copy = state->offset - copy;
          if (copy > state->whave) {
            if (state->sane) {
              strm->msg = (char *)"invalid distance too far back";
              state->mode = BAD;
              break;
            }
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
            Trace((stderr, "inflate.c too far\n"));
            copy -= state->whave;
            if (copy > state->length) copy = state->length;
            if (copy > left) copy = left;
            left -= copy;
            state->length -= copy;
            do {
              *put++ = 0;
            } while (--copy);
            if (state->length == 0) state->mode = LEN;
            break;
#endif
          }
          if (copy > state->wnext) {
            copy -= state->wnext;
            from = state->window + (state->wsize - copy);
          } else {
            from = state->window + (state->wnext - copy);
          }
          if (copy > state->length) copy = state->length;
          if (copy > left) copy = left;
          put = chunkcopy_safe(put, from, copy, put + left);
        } else { /* copy from output */
          copy = state->length;
          if (copy > left) copy = left;
          put = chunkcopy_lapped_safe(put, state->offset, copy, put + left);
        }
        left -= copy;
        state->length -= copy;
        if (state->length == 0) state->mode = LEN;
        break;
      case LIT:
        if (left == 0) goto inf_leave;
        *put++ = (unsigned char)(state->length);
        left--;
        state->mode = LEN;
        break;
      case CHECK:
        if (state->wrap) {
          NEEDBITS(32);
          out -= left;
          strm->total_out += out;
          state->total += out;
          if ((state->wrap & 4) && out)
            strm->adler = state->check = UPDATE(state->check, put - out, out);
          out = left;
          if ((state->wrap & 4) &&
              (
#ifdef GUNZIP
                  state->flags ? hold :
#endif
                               ZSWAP32(hold)) != state->check) {
            strm->msg = (char *)"incorrect data check";
            state->mode = BAD;
            break;
          }
          INITBITS();
          Tracev((stderr, "inflate:   check matches trailer\n"));
        }
#ifdef GUNZIP
        state->mode = LENGTH;
      case LENGTH:
        if (state->wrap && state->flags) {
          NEEDBITS(32);
          if (hold != (state->total & 0xffffffffUL)) {
            strm->msg = (char *)"incorrect length check";
            state->mode = BAD;
            break;
          }
          INITBITS();
          Tracev((stderr, "inflate:   length matches trailer\n"));
        }
#endif
        state->mode = DONE;
      case DONE:
        ret = Z_STREAM_END;
        goto inf_leave;
      case BAD:
        ret = Z_DATA_ERROR;
        goto inf_leave;
      case MEM:
        return Z_MEM_ERROR;
      case SYNC:
      default:
        return Z_STREAM_ERROR;
    }
  }

  /*
     Return from inflate(), updating the total counts and the check value.
     If there was no progress during the inflate() call, return a buffer
     error.  Call updatewindow() to create and/or update the window state.
     Note: a memory error from inflate() is non-recoverable.
   */
inf_leave:
  /* We write a defined value in the unused space to help mark
   * where the stream has ended. We don't use zeros as that can
   * mislead clients relying on undefined behavior (i.e. assuming
   * that the data is over when the buffer has a zero/null value).
   */
  if (left >= CHUNKCOPY_CHUNK_SIZE) {
    memset(put, 0x55, CHUNKCOPY_CHUNK_SIZE);
  } else {
    memset(put, 0x55, left);
  }

  RESTORE();
  if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
                       (state->mode < CHECK || flush != Z_FINISH)))
    if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
      state->mode = MEM;
      return Z_MEM_ERROR;
    }
  in -= strm->avail_in;
  out -= strm->avail_out;
  strm->total_in += in;
  strm->total_out += out;
  state->total += out;
  if ((state->wrap & 4) && out)
    strm->adler = state->check =
        UPDATE(state->check, strm->next_out - out, out);
  strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
                    (state->mode == TYPE ? 128 : 0) +
                    (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
  if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
    ret = Z_BUF_ERROR;
  return ret;
}

int inflateEnd(z_streamp strm) {
  struct InflateState *state;
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
  if (state->window != Z_NULL) ZFREE(strm, state->window);
  ZFREE(strm, strm->state);
  strm->state = Z_NULL;
  Tracev((stderr, "inflate: end\n"));
  return Z_OK;
}

int inflateGetDictionary(z_streamp strm, Bytef *dictionary, uInt *dictLength) {
  struct InflateState *state;

  /* check state */
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;

  /* copy dictionary */
  if (state->whave && dictionary != Z_NULL) {
    memcpy(dictionary, state->window + state->wnext,
           state->whave - state->wnext);
    memcpy(dictionary + state->whave - state->wnext, state->window,
           state->wnext);
  }
  if (dictLength != Z_NULL) *dictLength = state->whave;
  return Z_OK;
}

int inflateSetDictionary(z_streamp strm, const Bytef *dictionary,
                         uInt dictLength) {
  struct InflateState *state;
  unsigned long dictid;
  int ret;

  /* check state */
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
  if (state->wrap != 0 && state->mode != DICT) return Z_STREAM_ERROR;

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

  /* copy dictionary to window using updatewindow(), which will amend the
     existing dictionary if appropriate */
  ret = updatewindow(strm, dictionary + dictLength, dictLength);
  if (ret) {
    state->mode = MEM;
    return Z_MEM_ERROR;
  }
  state->havedict = 1;
  Tracev((stderr, "inflate:   dictionary set\n"));
  return Z_OK;
}

int inflateGetHeader(z_streamp strm, gz_headerp head) {
  struct InflateState *state;
  /* check state */
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
  if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
  /* save header structure */
  state->head = head;
  head->done = 0;
  return Z_OK;
}

/**
 * Searches buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when
 * found or when out of input. When called, *have is the number of
 * pattern bytes found in order so far, in 0..3. On return *have is
 * updated to the new state. If on return *have equals four, then the
 * pattern was found and the return value is how many bytes were read
 * including the last byte of the pattern. If *have is less than four,
 * then the pattern has not been found yet and the return value is len.
 * In the latter case, syncsearch() can be called again with more data
 * and the *have state. *have is initialized to zero for the first call.
 */
static unsigned syncsearch(unsigned *have, const unsigned char *buf,
                           unsigned len) {
  unsigned got;
  unsigned next;

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

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

  /* check parameters */
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
  if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;

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

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

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

/**
 * Returns true if inflate is currently at the end of a block generated
 * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
 * implementation to provide an additional safety check. PPP uses
 * Z_SYNC_FLUSH but removes the length bytes of the resulting empty
 * stored block. When decompressing, PPP checks that at the end of input
 * packet, inflate is waiting for these length bytes.
 */
int inflateSyncPoint(z_streamp strm) {
  struct InflateState *state;
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
  return state->mode == STORED && state->bits == 0;
}

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

  /* check input */
  if (inflateStateCheck(source) || dest == Z_NULL) return Z_STREAM_ERROR;
  state = (struct InflateState *)source->state;

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

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

int inflateUndermine(z_streamp strm, int subvert) {
  struct InflateState *state;
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
  state->sane = !subvert;
  return Z_OK;
#else
  (void)subvert;
  state->sane = 1;
  return Z_DATA_ERROR;
#endif
}

int inflateValidate(z_streamp strm, int check) {
  struct InflateState *state;
  if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
  state = (struct InflateState *)strm->state;
  if (check)
    state->wrap |= 4;
  else
    state->wrap &= ~4;
  return Z_OK;
}

long inflateMark(z_streamp strm) {
  struct InflateState *state;
  if (inflateStateCheck(strm)) return -(1L << 16);
  state = (struct InflateState *)strm->state;
  return (long)(((unsigned long)((long)state->back)) << 16) +
         (state->mode == COPY
              ? state->length
              : (state->mode == MATCH ? state->was - state->length : 0));
}

unsigned long inflateCodesUsed(z_streamp strm) {
  struct InflateState *state;
  if (inflateStateCheck(strm)) return (unsigned long)-1;
  state = (struct InflateState *)strm->state;
  return (unsigned long)(state->next - state->codes);
}