Update zlib to 1.2.5.

third_party/zlib/inflate.c

 /* inflate.c -- zlib decompression
- * Copyright (C) 1995-2005 Mark Adler
+ * Copyright (C) 1995-2010 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 /*
  * 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
@@ skipping 25 matching lines @@
  * - 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 write == 0 case for speed in inflate_fast()
+ * - Pull out common wnext == 0 case for speed in inflate_fast()
  * - Make op and len in inflate_fast() unsigned for consistency
  * - Add FAR 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
@@ skipping 51 matching lines @@
     strm->total_in = strm->total_out = state->total = 0;
     strm->msg = Z_NULL;
     strm->adler = 1;        /* to support ill-conceived Java test suite */
     state->mode = HEAD;
     state->last = 0;
     state->havedict = 0;
     state->dmax = 32768U;
     state->head = Z_NULL;
     state->wsize = 0;
     state->whave = 0;
-    state->write = 0;
+    state->wnext = 0;
     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 ZEXPORT inflatePrime(strm, bits, value)
+int ZEXPORT inflateReset2(strm, windowBits)
 z_streamp strm;
-int bits;
-int value;
+int windowBits;
 {
+    int wrap;
     struct inflate_state FAR *state;
 
+    /* get the state */
     if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
-    if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
-    value &= (1L << bits) - 1;
-    state->hold += value << state->bits;
-    state->bits += bits;
-    return Z_OK;
+
+    /* extract wrap request from windowBits parameter */
+    if (windowBits < 0) {
+        wrap = 0;
+        windowBits = -windowBits;
+    }
+    else {
+        wrap = (windowBits >> 4) + 1;
+#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 ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
 z_streamp strm;
 int windowBits;
 const char *version;
 int stream_size;
 {
+    int ret;
     struct inflate_state FAR *state;
 
     if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
         stream_size != (int)(sizeof(z_stream)))
         return Z_VERSION_ERROR;
     if (strm == Z_NULL) return Z_STREAM_ERROR;
     strm->msg = Z_NULL;                 /* in case we return an error */
     if (strm->zalloc == (alloc_func)0) {
         strm->zalloc = zcalloc;
         strm->opaque = (voidpf)0;
     }
     if (strm->zfree == (free_func)0) strm->zfree = zcfree;
     state = (struct inflate_state FAR *)
             ZALLOC(strm, 1, sizeof(struct inflate_state));
     if (state == Z_NULL) return Z_MEM_ERROR;
     Tracev((stderr, "inflate: allocated\n"));
     strm->state = (struct internal_state FAR *)state;
-    if (windowBits < 0) {
-        state->wrap = 0;
-        windowBits = -windowBits;
-    }
-    else {
-        state->wrap = (windowBits >> 4) + 1;
-#ifdef GUNZIP
-        if (windowBits < 48) windowBits &= 15;
-#endif
-    }
-    if (windowBits < 8 || windowBits > 15) {
+    state->window = Z_NULL;
+    ret = inflateReset2(strm, windowBits);
+    if (ret != Z_OK) {
         ZFREE(strm, state);
         strm->state = Z_NULL;
-        return Z_STREAM_ERROR;
     }
-    state->wbits = (unsigned)windowBits;
-    state->window = Z_NULL;
-    return inflateReset(strm);
+    return ret;
 }
 
 int ZEXPORT inflateInit_(strm, version, stream_size)
 z_streamp strm;
 const char *version;
 int stream_size;
 {
     return inflateInit2_(strm, DEF_WBITS, version, stream_size);
 }
 
+int ZEXPORT inflatePrime(strm, bits, value)
+z_streamp strm;
+int bits;
+int value;
+{
+    struct inflate_state FAR *state;
+
+    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (bits < 0) {
+        state->hold = 0;
+        state->bits = 0;
+        return Z_OK;
+    }
+    if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
+    value &= (1L << bits) - 1;
+    state->hold += value << state->bits;
+    state->bits += bits;
+    return Z_OK;
+}
+
 /*
    Return 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.
  */
@@ skipping 128 matching lines @@
     if (state->window == Z_NULL) {
         state->window = (unsigned char FAR *)
                         ZALLOC(strm, 1U << state->wbits,
                                sizeof(unsigned char));
         if (state->window == Z_NULL) return 1;
     }
 
     /* if window not in use yet, initialize */
     if (state->wsize == 0) {
         state->wsize = 1U << state->wbits;
-        state->write = 0;
+        state->wnext = 0;
         state->whave = 0;
     }
 
     /* copy state->wsize or less output bytes into the circular window */
     copy = out - strm->avail_out;
     if (copy >= state->wsize) {
         zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
-        state->write = 0;
+        state->wnext = 0;
         state->whave = state->wsize;
     }
     else {
-        dist = state->wsize - state->write;
+        dist = state->wsize - state->wnext;
         if (dist > copy) dist = copy;
-        zmemcpy(state->window + state->write, strm->next_out - copy, dist);
+        zmemcpy(state->window + state->wnext, strm->next_out - copy, dist);
         copy -= dist;
         if (copy) {
             zmemcpy(state->window, strm->next_out - copy, copy);
-            state->write = copy;
+            state->wnext = copy;
             state->whave = state->wsize;
         }
         else {
-            state->write += dist;
-            if (state->write == state->wsize) state->write = 0;
+            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
@@ skipping 180 matching lines @@
 {
     struct inflate_state FAR *state;
     unsigned char FAR *next;    /* next input */
     unsigned char FAR *put;     /* next output */
     unsigned have, left;        /* available input and output */
     unsigned long hold;         /* bit buffer */
     unsigned bits;              /* bits in bit buffer */
     unsigned in, out;           /* save starting available input and output */
     unsigned copy;              /* number of stored or match bytes to copy */
     unsigned char FAR *from;    /* where to copy match bytes from */
-    code this;                  /* current decoding table entry */
+    code here;                  /* current decoding table entry */
     code last;                  /* parent table entry */
     unsigned len;               /* length to copy for repeats, bits to drop */
     int ret;                    /* return code */
 #ifdef GUNZIP
     unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
 #endif
     static const unsigned short order[19] = /* permutation of code lengths */
         {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
 
     if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
@@ skipping 34 matching lines @@
                 state->mode = BAD;
                 break;
             }
             if (BITS(4) != Z_DEFLATED) {
                 strm->msg = (char *)"unknown compression method";
                 state->mode = BAD;
                 break;
             }
             DROPBITS(4);
             len = BITS(4) + 8;
-            if (len > state->wbits) {
+            if (state->wbits == 0)
+                state->wbits = len;
+            else if (len > state->wbits) {
                 strm->msg = (char *)"invalid window size";
                 state->mode = BAD;
                 break;
             }
             state->dmax = 1U << len;
             Tracev((stderr, "inflate:   zlib header ok\n"));
             strm->adler = state->check = adler32(0L, Z_NULL, 0);
             state->mode = hold & 0x200 ? DICTID : TYPE;
             INITBITS();
             break;
@@ skipping 131 matching lines @@
             INITBITS();
             state->mode = DICT;
         case DICT:
             if (state->havedict == 0) {
                 RESTORE();
                 return Z_NEED_DICT;
             }
             strm->adler = state->check = adler32(0L, Z_NULL, 0);
             state->mode = TYPE;
         case TYPE:
-            if (flush == Z_BLOCK) goto inf_leave;
+            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 */
+                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;
                 zmemcpy(put, next, copy);
                 have -= copy;
                 next += copy;
@@ skipping 40 matching lines @@
                 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 (;;) {
-                    this = state->lencode[BITS(state->lenbits)];
-                    if ((unsigned)(this.bits) <= bits) break;
+                    here = state->lencode[BITS(state->lenbits)];
+                    if ((unsigned)(here.bits) <= bits) break;
                     PULLBYTE();
                 }
-                if (this.val < 16) {
-                    NEEDBITS(this.bits);
-                    DROPBITS(this.bits);
-                    state->lens[state->have++] = this.val;
+                if (here.val < 16) {
+                    NEEDBITS(here.bits);
+                    DROPBITS(here.bits);
+                    state->lens[state->have++] = here.val;
                 }
                 else {
-                    if (this.val == 16) {
-                        NEEDBITS(this.bits + 2);
-                        DROPBITS(this.bits);
+                    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 (this.val == 17) {
-                        NEEDBITS(this.bits + 3);
-                        DROPBITS(this.bits);
+                    else if (here.val == 17) {
+                        NEEDBITS(here.bits + 3);
+                        DROPBITS(here.bits);
                         len = 0;
                         copy = 3 + BITS(3);
                         DROPBITS(3);
                     }
                     else {
-                        NEEDBITS(this.bits + 7);
-                        DROPBITS(this.bits);
+                        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;
 
-            /* build code tables */
+            /* 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 = (code const FAR *)(state->next);
             state->lenbits = 9;
             ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
                                 &(state->lenbits), state->work);
             if (ret) {
                 strm->msg = (char *)"invalid literal/lengths set";
                 state->mode = BAD;
                 break;
             }
             state->distcode = (code const FAR *)(state->next);
             state->distbits = 6;
             ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
                             &(state->next), &(state->distbits), state->work);
             if (ret) {
                 strm->msg = (char *)"invalid distances set";
                 state->mode = BAD;
                 break;
             }
             Tracev((stderr, "inflate:       codes ok\n"));
+            state->mode = LEN_;
+            if (flush == Z_TREES) goto inf_leave;
+        case LEN_:
             state->mode = LEN;
         case LEN:
             if (have >= 6 && left >= 258) {
                 RESTORE();
                 inflate_fast(strm, out);
                 LOAD();
+                if (state->mode == TYPE)
+                    state->back = -1;
                 break;
             }
+            state->back = 0;
             for (;;) {
-                this = state->lencode[BITS(state->lenbits)];
-                if ((unsigned)(this.bits) <= bits) break;
+                here = state->lencode[BITS(state->lenbits)];
+                if ((unsigned)(here.bits) <= bits) break;
                 PULLBYTE();
             }
-            if (this.op && (this.op & 0xf0) == 0) {
-                last = this;
+            if (here.op && (here.op & 0xf0) == 0) {
+                last = here;
                 for (;;) {
-                    this = state->lencode[last.val +
+                    here = state->lencode[last.val +
                             (BITS(last.bits + last.op) >> last.bits)];
-                    if ((unsigned)(last.bits + this.bits) <= bits) break;
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
                     PULLBYTE();
                 }
                 DROPBITS(last.bits);
+                state->back += last.bits;
             }
-            DROPBITS(this.bits);
-            state->length = (unsigned)this.val;
-            if ((int)(this.op) == 0) {
-                Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?
+            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", this.val));
+                        "inflate:         literal 0x%02x\n", here.val));
                 state->mode = LIT;
                 break;
             }
-            if (this.op & 32) {
+            if (here.op & 32) {
                 Tracevv((stderr, "inflate:         end of block\n"));
+                state->back = -1;
                 state->mode = TYPE;
                 break;
             }
-            if (this.op & 64) {
+            if (here.op & 64) {
                 strm->msg = (char *)"invalid literal/length code";
                 state->mode = BAD;
                 break;
             }
-            state->extra = (unsigned)(this.op) & 15;
+            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 (;;) {
-                this = state->distcode[BITS(state->distbits)];
-                if ((unsigned)(this.bits) <= bits) break;
+                here = state->distcode[BITS(state->distbits)];
+                if ((unsigned)(here.bits) <= bits) break;
                 PULLBYTE();
             }
-            if ((this.op & 0xf0) == 0) {
-                last = this;
+            if ((here.op & 0xf0) == 0) {
+                last = here;
                 for (;;) {
-                    this = state->distcode[last.val +
+                    here = state->distcode[last.val +
                             (BITS(last.bits + last.op) >> last.bits)];
-                    if ((unsigned)(last.bits + this.bits) <= bits) break;
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
                     PULLBYTE();
                 }
                 DROPBITS(last.bits);
+                state->back += last.bits;
             }
-            DROPBITS(this.bits);
-            if (this.op & 64) {
+            DROPBITS(here.bits);
+            state->back += here.bits;
+            if (here.op & 64) {
                 strm->msg = (char *)"invalid distance code";
                 state->mode = BAD;
                 break;
             }
-            state->offset = (unsigned)this.val;
-            state->extra = (unsigned)(this.op) & 15;
+            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
-            if (state->offset > state->whave + out - left) {
-                strm->msg = (char *)"invalid distance too far back";
-                state->mode = BAD;
-                break;
-            }
             Tracevv((stderr, "inflate:         distance %u\n", state->offset));
             state->mode = MATCH;
         case MATCH:
             if (left == 0) goto inf_leave;
             copy = out - left;
             if (state->offset > copy) {         /* copy from window */
                 copy = state->offset - copy;
-                if (copy > state->write) {
-                    copy -= state->write;
+                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->write - copy);
+                    from = state->window + (state->wnext - copy);
                 if (copy > state->length) copy = state->length;
             }
             else {                              /* copy from output */
                 from = put - state->offset;
                 copy = state->length;
             }
             if (copy > left) copy = left;
             left -= copy;
             state->length -= copy;
             do {
@@ skipping 72 matching lines @@
         }
     in -= strm->avail_in;
     out -= strm->avail_out;
     strm->total_in += in;
     strm->total_out += out;
     state->total += out;
     if (state->wrap && out)
         strm->adler = state->check =
             UPDATE(state->check, strm->next_out - out, out);
     strm->data_type = state->bits + (state->last ? 64 : 0) +
-                      (state->mode == TYPE ? 128 : 0);
+                      (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 ZEXPORT inflateEnd(strm)
 z_streamp strm;
 {
     struct inflate_state FAR *state;
     if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
@@ skipping 199 matching lines @@
     }
     copy->next = copy->codes + (state->next - state->codes);
     if (window != Z_NULL) {
         wsize = 1U << state->wbits;
         zmemcpy(window, state->window, wsize);
     }
     copy->window = window;
     dest->state = (struct internal_state FAR *)copy;
     return Z_OK;
 }
+
+int ZEXPORT inflateUndermine(strm, subvert)
+z_streamp strm;
+int subvert;
+{
+    struct inflate_state FAR *state;
+
+    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    state->sane = !subvert;
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+    return Z_OK;
+#else
+    state->sane = 1;
+    return Z_DATA_ERROR;
+#endif
+}
+
+long ZEXPORT inflateMark(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (strm == Z_NULL || strm->state == Z_NULL) return -1L << 16;
+    state = (struct inflate_state FAR *)strm->state;
+    return ((long)(state->back) << 16) +
+        (state->mode == COPY ? state->length :
+            (state->mode == MATCH ? state->was - state->length : 0));
+}