Update zlib to 1.2.5.

third_party/zlib/inftrees.c

 /* inftrees.c -- generate Huffman trees for efficient decoding
- * Copyright (C) 1995-2005 Mark Adler
+ * Copyright (C) 1995-2010 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 #include "zutil.h"
 #include "inftrees.h"
 
 #define MAXBITS 15
 
 const char inflate_copyright[] =
-   " inflate 1.2.3 Copyright 1995-2005 Mark Adler ";
+   " inflate 1.2.5 Copyright 1995-2010 Mark Adler ";
 /*
   If you use the zlib library in a product, an acknowledgment is welcome
   in the documentation of your product. If for some reason you cannot
   include such an acknowledgment, I would appreciate that you keep this
   copyright string in the executable of your product.
  */
 
 /*
    Build a set of tables to decode the provided canonical Huffman code.
    The code lengths are lens[0..codes-1].  The result starts at *table,
    whose indices are 0..2^bits-1.  work is a writable array of at least
    lens shorts, which is used as a work area.  type is the type of code
    to be generated, CODES, LENS, or DISTS.  On return, zero is success,
    -1 is an invalid code, and +1 means that ENOUGH isn't enough.  table
    on return points to the next available entry's address.  bits is the
    requested root table index bits, and on return it is the actual root
    table index bits.  It will differ if the request is greater than the
    longest code or if it is less than the shortest code.
  */
-int inflate_table(type, lens, codes, table, bits, work)
+int ZLIB_INTERNAL inflate_table(type, lens, codes, table, bits, work)
 codetype type;
 unsigned short FAR *lens;
 unsigned codes;
 code FAR * FAR *table;
 unsigned FAR *bits;
 unsigned short FAR *work;
 {
     unsigned len;               /* a code's length in bits */
     unsigned sym;               /* index of code symbols */
     unsigned min, max;          /* minimum and maximum code lengths */
     unsigned root;              /* number of index bits for root table */
     unsigned curr;              /* number of index bits for current table */
     unsigned drop;              /* code bits to drop for sub-table */
     int left;                   /* number of prefix codes available */
     unsigned used;              /* code entries in table used */
     unsigned huff;              /* Huffman code */
     unsigned incr;              /* for incrementing code, index */
     unsigned fill;              /* index for replicating entries */
     unsigned low;               /* low bits for current root entry */
     unsigned mask;              /* mask for low root bits */
-    code this;                  /* table entry for duplication */
+    code here;                  /* table entry for duplication */
     code FAR *next;             /* next available space in table */
     const unsigned short FAR *base;     /* base value table to use */
     const unsigned short FAR *extra;    /* extra bits table to use */
     int end;                    /* use base and extra for symbol > end */
     unsigned short count[MAXBITS+1];    /* number of codes of each length */
     unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
     static const unsigned short lbase[31] = { /* Length codes 257..285 base */
         3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
         35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
     static const unsigned short lext[31] = { /* Length codes 257..285 extra */
         16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
-        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 201, 196};
+        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 73, 195};
     static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
         1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
         257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
         8193, 12289, 16385, 24577, 0, 0};
     static const unsigned short dext[32] = { /* Distance codes 0..29 extra */
         16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22,
         23, 23, 24, 24, 25, 25, 26, 26, 27, 27,
         28, 28, 29, 29, 64, 64};
 
     /*
@@ skipping 32 matching lines @@
         count[len] = 0;
     for (sym = 0; sym < codes; sym++)
         count[lens[sym]]++;
 
     /* bound code lengths, force root to be within code lengths */
     root = *bits;
     for (max = MAXBITS; max >= 1; max--)
         if (count[max] != 0) break;
     if (root > max) root = max;
     if (max == 0) {                     /* no symbols to code at all */
-        this.op = (unsigned char)64;    /* invalid code marker */
-        this.bits = (unsigned char)1;
-        this.val = (unsigned short)0;
-        *(*table)++ = this;             /* make a table to force an error */
-        *(*table)++ = this;
+        here.op = (unsigned char)64;    /* invalid code marker */
+        here.bits = (unsigned char)1;
+        here.val = (unsigned short)0;
+        *(*table)++ = here;             /* make a table to force an error */
+        *(*table)++ = here;
         *bits = 1;
         return 0;     /* no symbols, but wait for decoding to report error */
     }
-    for (min = 1; min <= MAXBITS; min++)
+    for (min = 1; min < max; min++)
         if (count[min] != 0) break;
     if (root < min) root = min;
 
     /* check for an over-subscribed or incomplete set of lengths */
     left = 1;
     for (len = 1; len <= MAXBITS; len++) {
         left <<= 1;
         left -= count[len];
         if (left < 0) return -1;        /* over-subscribed */
     }
@@ skipping 22 matching lines @@
        of the low root bits of huff.  This is saved in low to check for when a
        new sub-table should be started.  drop is zero when the root table is
        being filled, and drop is root when sub-tables are being filled.
 
        When a new sub-table is needed, it is necessary to look ahead in the
        code lengths to determine what size sub-table is needed.  The length
        counts are used for this, and so count[] is decremented as codes are
        entered in the tables.
 
        used keeps track of how many table entries have been allocated from the
-       provided *table space.  It is checked when a LENS table is being made
-       against the space in *table, ENOUGH, minus the maximum space needed by
-       the worst case distance code, MAXD.  This should never happen, but the
-       sufficiency of ENOUGH has not been proven exhaustively, hence the check.
-       This assumes that when type == LENS, bits == 9.
+       provided *table space.  It is checked for LENS and DIST tables against
+       the constants ENOUGH_LENS and ENOUGH_DISTS to guard against changes in
+       the initial root table size constants.  See the comments in inftrees.h
+       for more information.
 
        sym increments through all symbols, and the loop terminates when
        all codes of length max, i.e. all codes, have been processed.  This
        routine permits incomplete codes, so another loop after this one fills
        in the rest of the decoding tables with invalid code markers.
      */
 
     /* set up for code type */
     switch (type) {
     case CODES:
@@ skipping 18 matching lines @@
     sym = 0;                    /* starting code symbol */
     len = min;                  /* starting code length */
     next = *table;              /* current table to fill in */
     curr = root;                /* current table index bits */
     drop = 0;                   /* current bits to drop from code for index */
     low = (unsigned)(-1);       /* trigger new sub-table when len > root */
     used = 1U << root;          /* use root table entries */
     mask = used - 1;            /* mask for comparing low */
 
     /* check available table space */
-    if (type == LENS && used >= ENOUGH - MAXD)
+    if ((type == LENS && used >= ENOUGH_LENS) ||
+        (type == DISTS && used >= ENOUGH_DISTS))
         return 1;
 
     /* process all codes and make table entries */
     for (;;) {
         /* create table entry */
-        this.bits = (unsigned char)(len - drop);
+        here.bits = (unsigned char)(len - drop);
         if ((int)(work[sym]) < end) {
-            this.op = (unsigned char)0;
-            this.val = work[sym];
+            here.op = (unsigned char)0;
+            here.val = work[sym];
         }
         else if ((int)(work[sym]) > end) {
-            this.op = (unsigned char)(extra[work[sym]]);
-            this.val = base[work[sym]];
+            here.op = (unsigned char)(extra[work[sym]]);
+            here.val = base[work[sym]];
         }
         else {
-            this.op = (unsigned char)(32 + 64);         /* end of block */
-            this.val = 0;
+            here.op = (unsigned char)(32 + 64);         /* end of block */
+            here.val = 0;
         }
 
         /* replicate for those indices with low len bits equal to huff */
         incr = 1U << (len - drop);
         fill = 1U << curr;
         min = fill;                 /* save offset to next table */
         do {
             fill -= incr;
-            next[(huff >> drop) + fill] = this;
+            next[(huff >> drop) + fill] = here;
         } while (fill != 0);
 
         /* backwards increment the len-bit code huff */
         incr = 1U << (len - 1);
         while (huff & incr)
             incr >>= 1;
         if (incr != 0) {
             huff &= incr - 1;
             huff += incr;
         }
@@ skipping 21 matching lines @@
             left = (int)(1 << curr);
             while (curr + drop < max) {
                 left -= count[curr + drop];
                 if (left <= 0) break;
                 curr++;
                 left <<= 1;
             }
 
             /* check for enough space */
             used += 1U << curr;
-            if (type == LENS && used >= ENOUGH - MAXD)
+            if ((type == LENS && used >= ENOUGH_LENS) ||
+                (type == DISTS && used >= ENOUGH_DISTS))
                 return 1;
 
             /* point entry in root table to sub-table */
             low = huff & mask;
             (*table)[low].op = (unsigned char)curr;
             (*table)[low].bits = (unsigned char)root;
             (*table)[low].val = (unsigned short)(next - *table);
         }
     }
 
     /*
        Fill in rest of table for incomplete codes.  This loop is similar to the
        loop above in incrementing huff for table indices.  It is assumed that
        len is equal to curr + drop, so there is no loop needed to increment
        through high index bits.  When the current sub-table is filled, the loop
        drops back to the root table to fill in any remaining entries there.
      */
-    this.op = (unsigned char)64;                /* invalid code marker */
-    this.bits = (unsigned char)(len - drop);
-    this.val = (unsigned short)0;
+    here.op = (unsigned char)64;                /* invalid code marker */
+    here.bits = (unsigned char)(len - drop);
+    here.val = (unsigned short)0;
     while (huff != 0) {
         /* when done with sub-table, drop back to root table */
         if (drop != 0 && (huff & mask) != low) {
             drop = 0;
             len = root;
             next = *table;
-            this.bits = (unsigned char)len;
+            here.bits = (unsigned char)len;
         }
 
         /* put invalid code marker in table */
-        next[huff >> drop] = this;
+        next[huff >> drop] = here;
 
         /* backwards increment the len-bit code huff */
         incr = 1U << (len - 1);
         while (huff & incr)
             incr >>= 1;
         if (incr != 0) {
             huff &= incr - 1;
             huff += incr;
         }
         else
             huff = 0;
     }
 
     /* set return parameters */
     *table += used;
     *bits = root;
     return 0;
 }