Update libvgz and neuter the adler32 bits we do not use.

lib/libvgz/adler32.c

@@ -7,6 +7,7 @@
 
 #include "zutil.h"
 
+#ifdef NOVGZ
 local uLong adler32_combine_ OF((uLong adler1, uLong adler2, z_off64_t len2));
 
 #define BASE 65521U     /* largest prime smaller than 65536 */
@@ -184,3 +185,15 @@ uLong ZEXPORT adler32_combine64(adler1, adler2, len2)
 {
     return adler32_combine_(adler1, adler2, len2);
 }
+#else
+uLong ZEXPORT adler32(adler, buf, len)
+    uLong adler;
+    const Bytef *buf;
+    uInt len;
+{
+	(void)adler;
+	(void)buf;
+	(void)len;
+	abort();
+}
+#endif

lib/libvgz/deflate.c

@@ -511,7 +511,7 @@ int ZEXPORT deflateResetKeep (strm)
         s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
 #endif
         adler32(0L, Z_NULL, 0);
-    s->last_flush = Z_NO_FLUSH;
+    s->last_flush = -2;
 
     _tr_init(s);
 
@@ -606,12 +606,12 @@ int ZEXPORT deflateParams(strm, level, strategy)
     func = configuration_table[s->level].func;
 
     if ((strategy != s->strategy || func != configuration_table[level].func) &&
-        s->high_water) {
+        s->last_flush != -2) {
         /* Flush the last buffer: */
         int err = deflate(strm, Z_BLOCK);
         if (err == Z_STREAM_ERROR)
             return err;
-        if (strm->avail_out == 0)
+        if (strm->avail_in || (s->strstart - s->block_start) + s->lookahead)
             return Z_BUF_ERROR;
     }
     if (s->level != level) {

lib/libvgz/trees.c

@@ -122,13 +122,13 @@ struct static_tree_desc_s {
     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};
 
 /* ===========================================================================

lib/libvgz/vgz.h

@@ -716,11 +716,12 @@ ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
    used to switch between compression and straight copy of the input data, or
    to switch to a different kind of input data requiring a different strategy.
    If the compression approach (which is a function of the level) or the
-   strategy is changed, and if any input has been consumed in a previous
-   deflate() call, then the input available so far is compressed with the old
-   level and strategy using deflate(strm, Z_BLOCK).  There are three approaches
-   for the compression levels 0, 1..3, and 4..9 respectively.  The new level
-   and strategy will take effect at the next call of deflate().
+   strategy is changed, and if there have been any deflate() calls since the
+   state was initialized or reset, then the input available so far is
+   compressed with the old level and strategy using deflate(strm, Z_BLOCK).
+   There are three approaches for the compression levels 0, 1..3, and 4..9
+   respectively.  The new level and strategy will take effect at the next call
+   of deflate().
 
      If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
    not have enough output space to complete, then the parameter change will not

tools/cmp_libz.sh

+#!/bin/sh
+
+# This script compares libvgz to zlib in FreeBSD source tree
+
+LZ=/usr/src/contrib/zlib
+
+if [ ! -d lib/libvgz ] ; then
+	echo "Run this from to of tree" 1>&2
+	exit 2
+fi
+
+for i in lib/libvgz/*.[ch]
+do
+	b=`basename $i`
+	if [ "$b" == "vgz.h" ] ; then
+		b="zlib.h"
+	fi
+	if [ -f ${LZ}/$b ] ; then
+		echo "==== $b"
+		sed '
+		s/vgz.h/zlib.h/
+		/strm->msg =/s/"/(char *)"/
+		' $i |
+		diff -u ${LZ}/$b -
+	else
+		echo "#### $b #### NOT FOUND ####"
+	fi
+done