--- a/zlib/trees.c	Sun Aug 21 07:07:55 2011 +0900
+++ b/zlib/trees.c	Fri Oct 27 22:46:09 2017 +0900
@@ -1,5 +1,6 @@
 /* trees.c -- output deflated data using Huffman coding
- * Copyright (C) 1995-2005 Jean-loup Gailly
+ * Copyright (C) 1995-2017 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
  */
 
@@ -35,7 +36,7 @@
 
 #include "deflate.h"
 
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
 #  include <ctype.h>
 #endif
 
@@ -73,11 +74,6 @@
  * 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.
  */
@@ -126,13 +122,13 @@
     int     max_length;          /* max bit length for the codes */
 };
 
-local static_tree_desc  static_l_desc =
+local const static_tree_desc  static_l_desc =
 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
 
-local static_tree_desc  static_d_desc =
+local const static_tree_desc  static_d_desc =
 {static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};
 
-local static_tree_desc  static_bl_desc =
+local const static_tree_desc  static_bl_desc =
 {(const ct_data *)0, extra_blbits, 0,   BL_CODES, MAX_BL_BITS};
 
 /* ===========================================================================
@@ -150,24 +146,22 @@
 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));
-local void copy_block     OF((deflate_state *s, charf *buf, unsigned len,
-                              int header));
 
 #ifdef GEN_TREES_H
 local void gen_trees_header OF((void));
 #endif
 
-#ifndef DEBUG
+#ifndef ZLIB_DEBUG
 #  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
    /* Send a code of the given tree. c and tree must not have side effects */
 
-#else /* DEBUG */
+#else /* !ZLIB_DEBUG */
 #  define send_code(s, c, tree) \
      { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
        send_bits(s, tree[c].Code, tree[c].Len); }
@@ -186,7 +180,7 @@
  * Send a value on a given number of bits.
  * IN assertion: length <= 16 and value fits in length bits.
  */
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
 local void send_bits      OF((deflate_state *s, int value, int length));
 
 local void send_bits(s, value, length)
@@ -203,31 +197,31 @@
      * 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;
     }
 }
-#else /* !DEBUG */
+#else /* !ZLIB_DEBUG */
 
 #define 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);\
+    int val = (int)value;\
+    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 */
+#endif /* ZLIB_DEBUG */
 
 
 /* the arguments must not have side effects */
@@ -250,11 +244,13 @@
     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;
@@ -319,7 +315,7 @@
  * Genererate the file trees.h describing the static trees.
  */
 #ifdef GEN_TREES_H
-#  ifndef DEBUG
+#  ifndef ZLIB_DEBUG
 #    include <stdio.h>
 #  endif
 
@@ -348,13 +344,14 @@
                 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, "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));
@@ -379,7 +376,7 @@
 /* ===========================================================================
  * Initialize the tree data structures for a new zlib stream.
  */
-void _tr_init(s)
+void ZLIB_INTERNAL _tr_init(s)
     deflate_state *s;
 {
     tr_static_init();
@@ -395,8 +392,7 @@
 
     s->bi_buf = 0;
     s->bi_valid = 0;
-    s->last_eob_len = 8; /* enough lookahead for inflate */
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
     s->compressed_len = 0L;
     s->bits_sent = 0L;
 #endif
@@ -524,12 +520,12 @@
         xbits = 0;
         if (n >= base) xbits = extra[n-base];
         f = tree[n].Freq;
-        s->opt_len += (ulg)f * (bits + xbits);
-        if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
+        s->opt_len += (ulg)f * (unsigned)(bits + xbits);
+        if (stree) s->static_len += (ulg)f * (unsigned)(stree[n].Len + xbits);
     }
     if (overflow == 0) return;
 
-    Trace((stderr,"\nbit length overflow\n"));
+    Tracev((stderr,"\nbit length overflow\n"));
     /* This happens for example on obj2 and pic of the Calgary corpus */
 
     /* Find the first bit length which could increase: */
@@ -556,9 +552,8 @@
             m = s->heap[--h];
             if (m > max_code) continue;
             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;
+                Tracev((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
+                s->opt_len += ((ulg)bits - tree[m].Len) * tree[m].Freq;
                 tree[m].Len = (ush)bits;
             }
             n--;
@@ -580,7 +575,7 @@
     ushf *bl_count;            /* number of codes at each bit length */
 {
     ush next_code[MAX_BITS+1]; /* next code value for each bit length */
-    ush code = 0;              /* running code value */
+    unsigned code = 0;         /* running code value */
     int bits;                  /* bit index */
     int n;                     /* code index */
 
@@ -588,7 +583,8 @@
      * without bit reversal.
      */
     for (bits = 1; bits <= MAX_BITS; bits++) {
-        next_code[bits] = code = (code + bl_count[bits-1]) << 1;
+        code = (code + bl_count[bits-1]) << 1;
+        next_code[bits] = (ush)code;
     }
     /* Check that the bit counts in bl_count are consistent. The last code
      * must be all ones.
@@ -601,7 +597,7 @@
         int len = tree[n].Len;
         if (len == 0) continue;
         /* Now reverse the bits */
-        tree[n].Code = bi_reverse(next_code[len]++, len);
+        tree[n].Code = (ush)bi_reverse(next_code[len]++, len);
 
         Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
              n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
@@ -823,7 +819,7 @@
         if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
     }
     /* Update opt_len to include the bit length tree and counts */
-    s->opt_len += 3*(max_blindex+1) + 5+5+4;
+    s->opt_len += 3*((ulg)max_blindex+1) + 5+5+4;
     Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
             s->opt_len, s->static_len));
 
@@ -864,65 +860,59 @@
 /* ===========================================================================
  * Send a stored block
  */
-void _tr_stored_block(s, buf, stored_len, eof)
+void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
     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 */
+    int last;         /* one if this is the last block for a file */
 {
-    send_bits(s, (STORED_BLOCK<<1)+eof, 3);  /* send block type */
-#ifdef DEBUG
+    send_bits(s, (STORED_BLOCK<<1)+last, 3);    /* send block type */
+    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);
+    s->pending += stored_len;
+#ifdef ZLIB_DEBUG
     s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
     s->compressed_len += (stored_len + 4) << 3;
+    s->bits_sent += 2*16;
+    s->bits_sent += stored_len<<3;
 #endif
-    copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
+}
+
+/* ===========================================================================
+ * Flush the bits in the bit buffer to pending output (leaves at most 7 bits)
+ */
+void ZLIB_INTERNAL _tr_flush_bits(s)
+    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)
+void ZLIB_INTERNAL _tr_align(s)
     deflate_state *s;
 {
     send_bits(s, STATIC_TREES<<1, 3);
     send_code(s, END_BLOCK, static_ltree);
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
     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.
+ * trees or store, and write out the encoded block.
  */
-void _tr_flush_block(s, buf, stored_len, eof)
+void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
     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 */
+    int last;         /* one if this is the last block for a file */
 {
     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 */
@@ -931,8 +921,8 @@
     if (s->level > 0) {
 
         /* Check if the file is binary or text */
-        if (stored_len > 0 && s->strm->data_type == Z_UNKNOWN)
-            set_data_type(s);
+        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)));
@@ -978,24 +968,26 @@
          * 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 (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);
-#ifdef DEBUG
+        send_bits(s, (STATIC_TREES<<1)+last, 3);
+        compress_block(s, (const ct_data *)static_ltree,
+                       (const ct_data *)static_dtree);
+#ifdef ZLIB_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);
-#ifdef DEBUG
+        compress_block(s, (const ct_data *)s->dyn_ltree,
+                       (const ct_data *)s->dyn_dtree);
+#ifdef ZLIB_DEBUG
         s->compressed_len += 3 + s->opt_len;
 #endif
     }
@@ -1005,21 +997,21 @@
      */
     init_block(s);
 
-    if (eof) {
+    if (last) {
         bi_windup(s);
-#ifdef DEBUG
+#ifdef ZLIB_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));
 }
 
 /* ===========================================================================
  * Save the match info and tally the frequency counts. Return true if
  * the current block must be flushed.
  */
-int _tr_tally (s, dist, lc)
+int ZLIB_INTERNAL _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) */
@@ -1071,8 +1063,8 @@
  */
 local void compress_block(s, ltree, dtree)
     deflate_state *s;
-    ct_data *ltree; /* literal tree */
-    ct_data *dtree; /* distance tree */
+    const ct_data *ltree; /* literal tree */
+    const ct_data *dtree; /* distance tree */
 {
     unsigned dist;      /* distance of matched string */
     int lc;             /* match length or unmatched char (if dist == 0) */
@@ -1102,7 +1094,7 @@
             send_code(s, code, dtree);       /* send the distance code */
             extra = extra_dbits[code];
             if (extra != 0) {
-                dist -= base_dist[code];
+                dist -= (unsigned)base_dist[code];
                 send_bits(s, dist, extra);   /* send the extra distance bits */
             }
         } /* literal or match pair ? */
@@ -1114,28 +1106,48 @@
     } while (lx < s->last_lit);
 
     send_code(s, END_BLOCK, ltree);
-    s->last_eob_len = ltree[END_BLOCK].Len;
 }
 
 /* ===========================================================================
- * Set the data type to BINARY or TEXT, using a crude approximation:
- * set it to Z_TEXT if all symbols are either printable characters (33 to 255)
- * or white spaces (9 to 13, or 32); or set it to Z_BINARY otherwise.
+ * 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)
+local int detect_data_type(s)
     deflate_state *s;
 {
+    /* 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;
 
-    for (n = 0; n < 9; 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)
-            break;
-    if (n == 9)
-        for (n = 14; n < 32; n++)
-            if (s->dyn_ltree[n].Freq != 0)
-                break;
-    s->strm->data_type = (n == 32) ? Z_TEXT : Z_BINARY;
+            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;
 }
 
 /* ===========================================================================
@@ -1185,35 +1197,7 @@
     }
     s->bi_buf = 0;
     s->bi_valid = 0;
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
     s->bits_sent = (s->bits_sent+7) & ~7;
 #endif
 }
-
-/* ===========================================================================
- * 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 */
-{
-    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);
-#ifdef DEBUG
-        s->bits_sent += 2*16;
-#endif
-    }
-#ifdef DEBUG
-    s->bits_sent += (ulg)len<<3;
-#endif
-    while (len--) {
-        put_byte(s, *buf++);
-    }
-}