Patch 15812 (Cyrez);

git-svn-id: https://pcsxr.svn.codeplex.com/svn/pcsxr@89133 e17a0e51-4ae3-4d35-97c3-1a29b211df97

1 files changed, 142 insertions, 168 deletions

diff --git a/win32/zlib/trees.c b/win32/zlib/trees.c
index 0a984056..7ff32a0a 100755
--- a/win32/zlib/trees.c
+++ b/win32/zlib/trees.c
@@ -1,6 +1,7 @@
 /* trees.c -- output deflated data using Huffman coding
- * Copyright (C) 1995-2002 Jean-loup Gailly
- * For conditions of distribution and use, see copyright notice in zlib.h 
+ * Copyright (C) 1995-2012 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
  */
 
 /*
@@ -35,6 +36,8 @@
 
 #include "deflate.h"
 
+#define ZLIB_NO__TR_TALLY
+
 #ifdef DEBUG
 #  include <ctype.h>
 #endif
@@ -73,11 +76,6 @@ local const uch bl_order[BL_CODES]
  * probability, to avoid transmitting the lengths for unused bit length codes.
  */
 
-#define Buf_size (8 * 2*sizeof(char))
-/* Number of bits used within bi_buf. (bi_buf might be implemented on
- * more than 16 bits on some systems.)
- */
-
 /* ===========================================================================
  * Local data. These are initialized only once.
  */
@@ -150,9 +148,9 @@ local void send_tree      OF((deflate_state *s, ct_data *tree, int max_code));
 local int  build_bl_tree  OF((deflate_state *s));
 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
                               int blcodes));
-local void compress_block OF((deflate_state *s, ct_data *ltree,
-                              ct_data *dtree));
-local void set_data_type  OF((deflate_state *s));
+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 void bi_windup      OF((deflate_state *s));
 local void bi_flush       OF((deflate_state *s));
@@ -203,12 +201,12 @@ local void send_bits(s, value, length)
      * unused bits in value.
      */
     if (s->bi_valid > (int)Buf_size - length) {
-        s->bi_buf |= (value << s->bi_valid);
+        s->bi_buf |= (ush)value << s->bi_valid;
         put_short(s, s->bi_buf);
         s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
         s->bi_valid += length - Buf_size;
     } else {
-        s->bi_buf |= value << s->bi_valid;
+        s->bi_buf |= (ush)value << s->bi_valid;
         s->bi_valid += length;
     }
 }
@@ -218,25 +216,24 @@ local void send_bits(s, value, length)
 { int len = length;\
   if (s->bi_valid > (int)Buf_size - len) {\
     int val = value;\
-    s->bi_buf |= (val << s->bi_valid);\
+    s->bi_buf |= (ush)val << s->bi_valid;\
     put_short(s, s->bi_buf);\
     s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
     s->bi_valid += len - Buf_size;\
   } else {\
-    s->bi_buf |= (value) << s->bi_valid;\
+    s->bi_buf |= (ush)(value) << s->bi_valid;\
     s->bi_valid += len;\
   }\
 }
 #endif /* DEBUG */
 
 
-#define MAX(a,b) (a >= b ? a : b)
 /* the arguments must not have side effects */
 
 /* ===========================================================================
  * Initialize the various 'constant' tables.
  */
-local void tr_static_init()
+local void tr_static_init(void)
 {
 #if defined(GEN_TREES_H) || !defined(STDC)
     static int static_init_done = 0;
@@ -251,11 +248,13 @@ local void tr_static_init()
     if (static_init_done) return;
 
     /* For some embedded targets, global variables are not initialized: */
+#ifdef NO_INIT_GLOBAL_POINTERS
     static_l_desc.static_tree = static_ltree;
     static_l_desc.extra_bits = extra_lbits;
     static_d_desc.static_tree = static_dtree;
     static_d_desc.extra_bits = extra_dbits;
     static_bl_desc.extra_bits = extra_blbits;
+#endif
 
     /* Initialize the mapping length (0..255) -> length code (0..28) */
     length = 0;
@@ -335,42 +334,43 @@ void gen_trees_header()
 
     Assert (header != NULL, "Can't open trees.h");
     fprintf(header,
-	    "/* header created automatically with -DGEN_TREES_H */\n\n");
+            "/* header created automatically with -DGEN_TREES_H */\n\n");
 
     fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
     for (i = 0; i < L_CODES+2; i++) {
-	fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
-		static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
+        fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
+                static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
     }
 
     fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
     for (i = 0; i < D_CODES; i++) {
-	fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
-		static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
+        fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
+                static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
     }
 
-    fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n");
+    fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");
     for (i = 0; i < DIST_CODE_LEN; i++) {
-	fprintf(header, "%2u%s", _dist_code[i],
-		SEPARATOR(i, DIST_CODE_LEN-1, 20));
+        fprintf(header, "%2u%s", _dist_code[i],
+                SEPARATOR(i, DIST_CODE_LEN-1, 20));
     }
 
-    fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
+    fprintf(header,
+        "const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
     for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
-	fprintf(header, "%2u%s", _length_code[i],
-		SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
+        fprintf(header, "%2u%s", _length_code[i],
+                SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
     }
 
     fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
     for (i = 0; i < LENGTH_CODES; i++) {
-	fprintf(header, "%1u%s", base_length[i],
-		SEPARATOR(i, LENGTH_CODES-1, 20));
+        fprintf(header, "%1u%s", base_length[i],
+                SEPARATOR(i, LENGTH_CODES-1, 20));
     }
 
     fprintf(header, "local const int base_dist[D_CODES] = {\n");
     for (i = 0; i < D_CODES; i++) {
-	fprintf(header, "%5u%s", base_dist[i],
-		SEPARATOR(i, D_CODES-1, 10));
+        fprintf(header, "%5u%s", base_dist[i],
+                SEPARATOR(i, D_CODES-1, 10));
     }
 
     fclose(header);
@@ -380,8 +380,7 @@ void gen_trees_header()
 /* ===========================================================================
  * Initialize the tree data structures for a new zlib stream.
  */
-void _tr_init(s)
-    deflate_state *s;
+void ZLIB_INTERNAL _tr_init(deflate_state *s)
 {
     tr_static_init();
 
@@ -396,7 +395,6 @@ void _tr_init(s)
 
     s->bi_buf = 0;
     s->bi_valid = 0;
-    s->last_eob_len = 8; /* enough lookahead for inflate */
 #ifdef DEBUG
     s->compressed_len = 0L;
     s->bits_sent = 0L;
@@ -409,8 +407,7 @@ void _tr_init(s)
 /* ===========================================================================
  * Initialize a new block.
  */
-local void init_block(s)
-    deflate_state *s;
+local void init_block(deflate_state *s)
 {
     int n; /* iterates over tree elements */
 
@@ -453,10 +450,7 @@ local void init_block(s)
  * when the heap property is re-established (each father smaller than its
  * two sons).
  */
-local void pqdownheap(s, tree, k)
-    deflate_state *s;
-    ct_data *tree;  /* the tree to restore */
-    int k;               /* node to move down */
+local void pqdownheap(deflate_state *s, ct_data *tree, int k)
 {
     int v = s->heap[k];
     int j = k << 1;  /* left son of k */
@@ -488,9 +482,7 @@ local void pqdownheap(s, tree, k)
  *     The length opt_len is updated; static_len is also updated if stree is
  *     not null.
  */
-local void gen_bitlen(s, desc)
-    deflate_state *s;
-    tree_desc *desc;    /* the tree descriptor */
+local void gen_bitlen(deflate_state *s, tree_desc *desc)
 {
     ct_data *tree        = desc->dyn_tree;
     int max_code         = desc->max_code;
@@ -556,7 +548,7 @@ local void gen_bitlen(s, desc)
         while (n != 0) {
             m = s->heap[--h];
             if (m > max_code) continue;
-            if (tree[m].Len != (unsigned) bits) {
+            if ((unsigned) tree[m].Len != (unsigned) bits) {
                 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
                 s->opt_len += ((long)bits - (long)tree[m].Len)
                               *(long)tree[m].Freq;
@@ -575,10 +567,7 @@ local void gen_bitlen(s, desc)
  * OUT assertion: the field code is set for all tree elements of non
  *     zero code length.
  */
-local void gen_codes (tree, max_code, bl_count)
-    ct_data *tree;             /* the tree to decorate */
-    int max_code;              /* largest code with non zero frequency */
-    ushf *bl_count;            /* number of codes at each bit length */
+local void gen_codes (ct_data *tree, int max_code, ushf *bl_count)
 {
     ush next_code[MAX_BITS+1]; /* next code value for each bit length */
     ush code = 0;              /* running code value */
@@ -617,9 +606,7 @@ local void gen_codes (tree, max_code, bl_count)
  *     and corresponding code. The length opt_len is updated; static_len is
  *     also updated if stree is not null. The field max_code is set.
  */
-local void build_tree(s, desc)
-    deflate_state *s;
-    tree_desc *desc; /* the tree descriptor */
+local void build_tree(deflate_state *s, tree_desc *desc)
 {
     ct_data *tree         = desc->dyn_tree;
     const ct_data *stree  = desc->stat_desc->static_tree;
@@ -675,7 +662,8 @@ local void build_tree(s, desc)
 
         /* Create a new node father of n and m */
         tree[node].Freq = tree[n].Freq + tree[m].Freq;
-        s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
+        s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?
+                                s->depth[n] : s->depth[m]) + 1);
         tree[n].Dad = tree[m].Dad = (ush)node;
 #ifdef DUMP_BL_TREE
         if (tree == s->bl_tree) {
@@ -704,10 +692,7 @@ local void build_tree(s, desc)
  * Scan a literal or distance tree to determine the frequencies of the codes
  * in the bit length tree.
  */
-local void scan_tree (s, tree, max_code)
-    deflate_state *s;
-    ct_data *tree;   /* the tree to be scanned */
-    int max_code;    /* and its largest code of non zero frequency */
+local void scan_tree (deflate_state *s, ct_data *tree, int max_code)
 {
     int n;                     /* iterates over all tree elements */
     int prevlen = -1;          /* last emitted length */
@@ -749,10 +734,7 @@ local void scan_tree (s, tree, max_code)
  * Send a literal or distance tree in compressed form, using the codes in
  * bl_tree.
  */
-local void send_tree (s, tree, max_code)
-    deflate_state *s;
-    ct_data *tree; /* the tree to be scanned */
-    int max_code;       /* and its largest code of non zero frequency */
+local void send_tree (deflate_state *s, ct_data *tree, int max_code)
 {
     int n;                     /* iterates over all tree elements */
     int prevlen = -1;          /* last emitted length */
@@ -800,8 +782,7 @@ local void send_tree (s, tree, max_code)
  * Construct the Huffman tree for the bit lengths and return the index in
  * bl_order of the last bit length code to send.
  */
-local int build_bl_tree(s)
-    deflate_state *s;
+local int build_bl_tree(deflate_state *s)
 {
     int max_blindex;  /* index of last bit length code of non zero freq */
 
@@ -835,9 +816,8 @@ local int build_bl_tree(s)
  * lengths of the bit length codes, the literal tree and the distance tree.
  * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
  */
-local void send_all_trees(s, lcodes, dcodes, blcodes)
-    deflate_state *s;
-    int lcodes, dcodes, blcodes; /* number of codes for each tree */
+local void send_all_trees(deflate_state *s, int lcodes, int dcodes,
+                          int blcodes)
 {
     int rank;                    /* index in bl_order */
 
@@ -864,13 +844,10 @@ local void send_all_trees(s, lcodes, dcodes, blcodes)
 /* ===========================================================================
  * Send a stored block
  */
-void _tr_stored_block(s, buf, stored_len, eof)
-    deflate_state *s;
-    charf *buf;       /* input block */
-    ulg stored_len;   /* length of input block */
-    int eof;          /* true if this is the last block for a file */
+void ZLIB_INTERNAL _tr_stored_block(deflate_state *s, charf *buf,
+									ulg stored_len, int last)
 {
-    send_bits(s, (STORED_BLOCK<<1)+eof, 3);  /* send block type */
+    send_bits(s, (STORED_BLOCK<<1)+last, 3);    /* send block type */
 #ifdef DEBUG
     s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
     s->compressed_len += (stored_len + 4) << 3;
@@ -879,18 +856,18 @@ void _tr_stored_block(s, buf, stored_len, eof)
 }
 
 /* ===========================================================================
+ * Flush the bits in the bit buffer to pending output (leaves at most 7 bits)
+ */
+void ZLIB_INTERNAL _tr_flush_bits(deflate_state *s)
+{
+    bi_flush(s);
+}
+
+/* ===========================================================================
  * Send one empty static block to give enough lookahead for inflate.
  * This takes 10 bits, of which 7 may remain in the bit buffer.
- * The current inflate code requires 9 bits of lookahead. If the
- * last two codes for the previous block (real code plus EOB) were coded
- * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
- * the last real code. In this case we send two empty static blocks instead
- * of one. (There are no problems if the previous block is stored or fixed.)
- * To simplify the code, we assume the worst case of last real code encoded
- * on one bit only.
  */
-void _tr_align(s)
-    deflate_state *s;
+void ZLIB_INTERNAL _tr_align(deflate_state *s)
 {
     send_bits(s, STATIC_TREES<<1, 3);
     send_code(s, END_BLOCK, static_ltree);
@@ -898,31 +875,14 @@ void _tr_align(s)
     s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
 #endif
     bi_flush(s);
-    /* Of the 10 bits for the empty block, we have already sent
-     * (10 - bi_valid) bits. The lookahead for the last real code (before
-     * the EOB of the previous block) was thus at least one plus the length
-     * of the EOB plus what we have just sent of the empty static block.
-     */
-    if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
-        send_bits(s, STATIC_TREES<<1, 3);
-        send_code(s, END_BLOCK, static_ltree);
-#ifdef DEBUG
-        s->compressed_len += 10L;
-#endif
-        bi_flush(s);
-    }
-    s->last_eob_len = 7;
 }
 
 /* ===========================================================================
  * Determine the best encoding for the current block: dynamic trees, static
  * trees or store, and output the encoded block to the zip file.
  */
-void _tr_flush_block(s, buf, stored_len, eof)
-    deflate_state *s;
-    charf *buf;       /* input block, or NULL if too old */
-    ulg stored_len;   /* length of input block */
-    int eof;          /* true if this is the last block for a file */
+void ZLIB_INTERNAL _tr_flush_block(deflate_state *s, charf *buf,
+                                   ulg stored_len, int last)
 {
     ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
     int max_blindex = 0;  /* index of last bit length code of non zero freq */
@@ -930,39 +890,40 @@ void _tr_flush_block(s, buf, stored_len, eof)
     /* Build the Huffman trees unless a stored block is forced */
     if (s->level > 0) {
 
-	 /* Check if the file is ascii or binary */
-	if (s->data_type == Z_UNKNOWN) set_data_type(s);
+        /* Check if the file is binary or text */
+        if (s->strm->data_type == Z_UNKNOWN)
+            s->strm->data_type = detect_data_type(s);
 
-	/* Construct the literal and distance trees */
-	build_tree(s, (tree_desc *)(&(s->l_desc)));
-	Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
-		s->static_len));
+        /* Construct the literal and distance trees */
+        build_tree(s, (tree_desc *)(&(s->l_desc)));
+        Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
+                s->static_len));
 
-	build_tree(s, (tree_desc *)(&(s->d_desc)));
-	Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
-		s->static_len));
-	/* At this point, opt_len and static_len are the total bit lengths of
-	 * the compressed block data, excluding the tree representations.
-	 */
+        build_tree(s, (tree_desc *)(&(s->d_desc)));
+        Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
+                s->static_len));
+        /* At this point, opt_len and static_len are the total bit lengths of
+         * the compressed block data, excluding the tree representations.
+         */
 
-	/* Build the bit length tree for the above two trees, and get the index
-	 * in bl_order of the last bit length code to send.
-	 */
-	max_blindex = build_bl_tree(s);
+        /* Build the bit length tree for the above two trees, and get the index
+         * in bl_order of the last bit length code to send.
+         */
+        max_blindex = build_bl_tree(s);
 
-	/* Determine the best encoding. Compute first the block length in bytes*/
-	opt_lenb = (s->opt_len+3+7)>>3;
-	static_lenb = (s->static_len+3+7)>>3;
+        /* Determine the best encoding. Compute the block lengths in bytes. */
+        opt_lenb = (s->opt_len+3+7)>>3;
+        static_lenb = (s->static_len+3+7)>>3;
 
-	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));
+        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));
 
-	if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
+        if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
 
     } else {
         Assert(buf != (char*)0, "lost buf");
-	opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
+        opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
     }
 
 #ifdef FORCE_STORED
@@ -977,23 +938,25 @@ void _tr_flush_block(s, buf, stored_len, eof)
          * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
          * transform a block into a stored block.
          */
-        _tr_stored_block(s, buf, stored_len, eof);
+        _tr_stored_block(s, buf, stored_len, last);
 
 #ifdef FORCE_STATIC
     } else if (static_lenb >= 0) { /* force static trees */
 #else
-    } else if (static_lenb == opt_lenb) {
+    } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
 #endif
-        send_bits(s, (STATIC_TREES<<1)+eof, 3);
-        compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
+        send_bits(s, (STATIC_TREES<<1)+last, 3);
+        compress_block(s, (const ct_data *)static_ltree,
+                       (const ct_data *)static_dtree);
 #ifdef DEBUG
         s->compressed_len += 3 + s->static_len;
 #endif
     } else {
-        send_bits(s, (DYN_TREES<<1)+eof, 3);
+        send_bits(s, (DYN_TREES<<1)+last, 3);
         send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
                        max_blindex+1);
-        compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
+        compress_block(s, (const ct_data *)s->dyn_ltree,
+                       (const ct_data *)s->dyn_dtree);
 #ifdef DEBUG
         s->compressed_len += 3 + s->opt_len;
 #endif
@@ -1004,24 +967,22 @@ void _tr_flush_block(s, buf, stored_len, eof)
      */
     init_block(s);
 
-    if (eof) {
+    if (last) {
         bi_windup(s);
 #ifdef DEBUG
         s->compressed_len += 7;  /* align on byte boundary */
 #endif
     }
     Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
-           s->compressed_len-7*eof));
+           s->compressed_len-7*last));
 }
 
+#ifndef ZLIB_NO__TR_TALLY
 /* ===========================================================================
  * Save the match info and tally the frequency counts. Return true if
  * the current block must be flushed.
  */
-int _tr_tally (s, dist, lc)
-    deflate_state *s;
-    unsigned dist;  /* distance of matched string */
-    unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
+int ZLIB_INTERNAL _tr_tally (deflate_state *s, unsigned dist, unsigned lc)
 {
     s->d_buf[s->last_lit] = (ush)dist;
     s->l_buf[s->last_lit++] = (uch)lc;
@@ -1064,14 +1025,13 @@ int _tr_tally (s, dist, lc)
      * 64K-1 bytes.
      */
 }
+#endif
 
 /* ===========================================================================
  * Send the block data compressed using the given Huffman trees
  */
-local void compress_block(s, ltree, dtree)
-    deflate_state *s;
-    ct_data *ltree; /* literal tree */
-    ct_data *dtree; /* distance tree */
+local void compress_block(deflate_state *s, const ct_data *ltree,
+                          const ct_data *dtree)
 {
     unsigned dist;      /* distance of matched string */
     int lc;             /* match length or unmatched char (if dist == 0) */
@@ -1107,30 +1067,53 @@ 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(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
+        Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
+               "pendingBuf overflow");
 
     } while (lx < s->last_lit);
 
     send_code(s, END_BLOCK, ltree);
-    s->last_eob_len = ltree[END_BLOCK].Len;
 }
 
 /* ===========================================================================
- * Set the data type to ASCII or BINARY, using a crude approximation:
- * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
- * IN assertion: the fields freq of dyn_ltree are set and the total of all
- * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
+ * 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).
+ *    b) There is at least one printable character belonging to the
+ *       "white 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:
+ *   (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
+ * IN assertion: the fields Freq of dyn_ltree are set.
  */
-local void set_data_type(s)
-    deflate_state *s;
+local int detect_data_type(deflate_state *s)
 {
-    int n = 0;
-    unsigned ascii_freq = 0;
-    unsigned bin_freq = 0;
-    while (n < 7)        bin_freq += s->dyn_ltree[n++].Freq;
-    while (n < 128)    ascii_freq += s->dyn_ltree[n++].Freq;
-    while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
-    s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
+    /* black_mask is the bit mask of black-listed bytes
+     * set bits 0..6, 14..25, and 28..31
+     * 0xf3ffc07f = binary 11110011111111111100000001111111
+     */
+    unsigned long black_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))
+            return Z_BINARY;
+
+    /* Check for textual ("white-listed") bytes. */
+    if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
+            || s->dyn_ltree[13].Freq != 0)
+        return Z_TEXT;
+    for (n = 32; n < LITERALS; n++)
+        if (s->dyn_ltree[n].Freq != 0)
+            return Z_TEXT;
+
+    /* There are no "black-listed" or "white-listed" bytes:
+     * this stream either is empty or has tolerated ("gray-listed") bytes only.
+     */
+    return Z_BINARY;
 }
 
 /* ===========================================================================
@@ -1138,9 +1121,7 @@ local void set_data_type(s)
  * method would use a table)
  * IN assertion: 1 <= len <= 15
  */
-local unsigned bi_reverse(code, len)
-    unsigned code; /* the value to invert */
-    int len;       /* its bit length */
+local unsigned bi_reverse(unsigned code, int len)
 {
     register unsigned res = 0;
     do {
@@ -1153,8 +1134,7 @@ local unsigned bi_reverse(code, len)
 /* ===========================================================================
  * Flush the bit buffer, keeping at most 7 bits in it.
  */
-local void bi_flush(s)
-    deflate_state *s;
+local void bi_flush(deflate_state *s)
 {
     if (s->bi_valid == 16) {
         put_short(s, s->bi_buf);
@@ -1170,8 +1150,7 @@ local void bi_flush(s)
 /* ===========================================================================
  * Flush the bit buffer and align the output on a byte boundary
  */
-local void bi_windup(s)
-    deflate_state *s;
+local void bi_windup(deflate_state *s)
 {
     if (s->bi_valid > 8) {
         put_short(s, s->bi_buf);
@@ -1189,17 +1168,12 @@ local void bi_windup(s)
  * Copy a stored block, storing first the length and its
  * one's complement if requested.
  */
-local void copy_block(s, buf, len, header)
-    deflate_state *s;
-    charf    *buf;    /* the input data */
-    unsigned len;     /* its length */
-    int      header;  /* true if block header must be written */
+local void copy_block(deflate_state *s, charf *buf, unsigned len, int header)
 {
     bi_windup(s);        /* align on byte boundary */
-    s->last_eob_len = 8; /* enough lookahead for inflate */
 
     if (header) {
-        put_short(s, (ush)len);   
+        put_short(s, (ush)len);
         put_short(s, (ush)~len);
 #ifdef DEBUG
         s->bits_sent += 2*16;