1 files changed, 27 insertions, 48 deletions

diff --git a/zlib/trees.c b/zlib/trees.c
index 50cf4b45..f73fd99c 100644
--- a/zlib/trees.c
+++ b/zlib/trees.c
@@ -1,5 +1,5 @@
 /* trees.c -- output deflated data using Huffman coding
- * Copyright (C) 1995-2017 Jean-loup Gailly
+ * Copyright (C) 1995-2021 Jean-loup Gailly
  * detect_data_type() function provided freely by Cosmin Truta, 2006
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
@@ -149,7 +149,7 @@ local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
 local void compress_block OF((deflate_state *s, const ct_data *ltree,
                               const ct_data *dtree));
 local int  detect_data_type OF((deflate_state *s));
-local unsigned bi_reverse OF((unsigned value, int length));
+local unsigned bi_reverse OF((unsigned code, int len));
 local void bi_windup      OF((deflate_state *s));
 local void bi_flush       OF((deflate_state *s));
 
@@ -416,7 +416,7 @@ local void init_block(s)
 
     s->dyn_ltree[END_BLOCK].Freq = 1;
     s->opt_len = s->static_len = 0L;
-    s->last_lit = s->matches = 0;
+    s->sym_next = s->matches = 0;
 }
 
 #define SMALLEST 1
@@ -870,7 +870,8 @@ void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
     bi_windup(s);        /* align on byte boundary */
     put_short(s, (ush)stored_len);
     put_short(s, (ush)~stored_len);
-    zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
+    if (stored_len)
+        zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
     s->pending += stored_len;
 #ifdef ZLIB_DEBUG
     s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
@@ -947,7 +948,7 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
 
         Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
                 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
-                s->last_lit));
+                s->sym_next / 3));
 
         if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
 
@@ -1016,8 +1017,9 @@ int ZLIB_INTERNAL _tr_tally (s, dist, lc)
     unsigned dist;  /* distance of matched string */
     unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
 {
-    s->d_buf[s->last_lit] = (ush)dist;
-    s->l_buf[s->last_lit++] = (uch)lc;
+    s->sym_buf[s->sym_next++] = dist;
+    s->sym_buf[s->sym_next++] = dist >> 8;
+    s->sym_buf[s->sym_next++] = lc;
     if (dist == 0) {
         /* lc is the unmatched char */
         s->dyn_ltree[lc].Freq++;
@@ -1032,30 +1034,7 @@ int ZLIB_INTERNAL _tr_tally (s, dist, lc)
         s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
         s->dyn_dtree[d_code(dist)].Freq++;
     }
-
-#ifdef TRUNCATE_BLOCK
-    /* Try to guess if it is profitable to stop the current block here */
-    if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
-        /* Compute an upper bound for the compressed length */
-        ulg out_length = (ulg)s->last_lit*8L;
-        ulg in_length = (ulg)((long)s->strstart - s->block_start);
-        int dcode;
-        for (dcode = 0; dcode < D_CODES; dcode++) {
-            out_length += (ulg)s->dyn_dtree[dcode].Freq *
-                (5L+extra_dbits[dcode]);
-        }
-        out_length >>= 3;
-        Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
-               s->last_lit, in_length, out_length,
-               100L - out_length*100L/in_length));
-        if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
-    }
-#endif
-    return (s->last_lit == s->lit_bufsize-1);
-    /* We avoid equality with lit_bufsize because of wraparound at 64K
-     * on 16 bit machines and because stored blocks are restricted to
-     * 64K-1 bytes.
-     */
+    return (s->sym_next == s->sym_end);
 }
 
 /* ===========================================================================
@@ -1068,13 +1047,14 @@ local void compress_block(s, ltree, dtree)
 {
     unsigned dist;      /* distance of matched string */
     int lc;             /* match length or unmatched char (if dist == 0) */
-    unsigned lx = 0;    /* running index in l_buf */
+    unsigned sx = 0;    /* running index in sym_buf */
     unsigned code;      /* the code to send */
     int extra;          /* number of extra bits to send */
 
-    if (s->last_lit != 0) do {
-        dist = s->d_buf[lx];
-        lc = s->l_buf[lx++];
+    if (s->sym_next != 0) do {
+        dist = s->sym_buf[sx++] & 0xff;
+        dist += (unsigned)(s->sym_buf[sx++] & 0xff) << 8;
+        lc = s->sym_buf[sx++];
         if (dist == 0) {
             send_code(s, lc, ltree); /* send a literal byte */
             Tracecv(isgraph(lc), (stderr," '%c' ", lc));
@@ -1099,11 +1079,10 @@ local void compress_block(s, ltree, dtree)
             }
         } /* literal or match pair ? */
 
-        /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
-        Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
-               "pendingBuf overflow");
+        /* Check that the overlay between pending_buf and sym_buf is ok: */
+        Assert(s->pending < s->lit_bufsize + sx, "pendingBuf overflow");
 
-    } while (lx < s->last_lit);
+    } while (sx < s->sym_next);
 
     send_code(s, END_BLOCK, ltree);
 }
@@ -1112,9 +1091,9 @@ local void compress_block(s, ltree, dtree)
  * Check if the data type is TEXT or BINARY, using the following algorithm:
  * - TEXT if the two conditions below are satisfied:
  *    a) There are no non-portable control characters belonging to the
- *       "black list" (0..6, 14..25, 28..31).
+ *       "block list" (0..6, 14..25, 28..31).
  *    b) There is at least one printable character belonging to the
- *       "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
+ *       "allow list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
  * - BINARY otherwise.
  * - The following partially-portable control characters form a
  *   "gray list" that is ignored in this detection algorithm:
@@ -1124,19 +1103,19 @@ local void compress_block(s, ltree, dtree)
 local int detect_data_type(s)
     deflate_state *s;
 {
-    /* black_mask is the bit mask of black-listed bytes
+    /* block_mask is the bit mask of block-listed bytes
      * set bits 0..6, 14..25, and 28..31
      * 0xf3ffc07f = binary 11110011111111111100000001111111
      */
-    unsigned long black_mask = 0xf3ffc07fUL;
+    unsigned long block_mask = 0xf3ffc07fUL;
     int n;
 
-    /* Check for non-textual ("black-listed") bytes. */
-    for (n = 0; n <= 31; n++, black_mask >>= 1)
-        if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
+    /* Check for non-textual ("block-listed") bytes. */
+    for (n = 0; n <= 31; n++, block_mask >>= 1)
+        if ((block_mask & 1) && (s->dyn_ltree[n].Freq != 0))
             return Z_BINARY;
 
-    /* Check for textual ("white-listed") bytes. */
+    /* Check for textual ("allow-listed") bytes. */
     if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
             || s->dyn_ltree[13].Freq != 0)
         return Z_TEXT;
@@ -1144,7 +1123,7 @@ local int detect_data_type(s)
         if (s->dyn_ltree[n].Freq != 0)
             return Z_TEXT;
 
-    /* There are no "black-listed" or "white-listed" bytes:
+    /* There are no "block-listed" or "allow-listed" bytes:
      * this stream either is empty or has tolerated ("gray-listed") bytes only.
      */
     return Z_BINARY;