diff --git a/lib/libz/adler32.c b/lib/libz/adler32.c
index b1f71ce05fe6..16cf9a703f7c 100644
--- a/lib/libz/adler32.c
+++ b/lib/libz/adler32.c
@@ -3,7 +3,7 @@
  * For conditions of distribution and use, see copyright notice in zlib.h 
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id$ */
 
 #include "zlib.h"
 
diff --git a/lib/libz/compress.c b/lib/libz/compress.c
index 31c51e611659..1cee470913d7 100644
--- a/lib/libz/compress.c
+++ b/lib/libz/compress.c
@@ -3,7 +3,7 @@
  * For conditions of distribution and use, see copyright notice in zlib.h 
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id$ */
 
 #include "zlib.h"
 
diff --git a/lib/libz/crc32.c b/lib/libz/crc32.c
index 2e98580b0b95..a91101a81c6a 100644
--- a/lib/libz/crc32.c
+++ b/lib/libz/crc32.c
@@ -3,7 +3,7 @@
  * For conditions of distribution and use, see copyright notice in zlib.h 
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id$ */
 
 #include "zlib.h"
 
diff --git a/lib/libz/deflate.c b/lib/libz/deflate.c
index dc8c76c51372..cfa05059d3ff 100644
--- a/lib/libz/deflate.c
+++ b/lib/libz/deflate.c
@@ -47,12 +47,12 @@
  *
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id: deflate.c,v 1.1.1.3 1999/01/10 09:46:53 peter Exp $ */
 
 #include "deflate.h"
 
 const char deflate_copyright[] =
-   " deflate 1.1.1 Copyright 1995-1998 Jean-loup Gailly ";
+   " deflate 1.1.3 Copyright 1995-1998 Jean-loup Gailly ";
 /*
   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
@@ -608,11 +608,13 @@ int ZEXPORT deflateCopy (dest, source)
     deflate_state *ss;
     ushf *overlay;
 
-    ss = source->state;
 
-    if (source == Z_NULL || dest == Z_NULL || ss == Z_NULL) {
+    if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
         return Z_STREAM_ERROR;
     }
+
+    ss = source->state;
+
     *dest = *source;
 
     ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
diff --git a/lib/libz/deflate.h b/lib/libz/deflate.h
index 5cf65ec89f1e..112a15e0f443 100644
--- a/lib/libz/deflate.h
+++ b/lib/libz/deflate.h
@@ -8,7 +8,7 @@
    subject to change. Applications should only use zlib.h.
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id: deflate.h,v 1.1.1.3 1999/01/10 09:46:53 peter Exp $ */
 
 #ifndef _DEFLATE_H
 #define _DEFLATE_H
@@ -230,12 +230,12 @@ typedef struct internal_state {
 
     ulg opt_len;        /* bit length of current block with optimal trees */
     ulg static_len;     /* bit length of current block with static trees */
-    ulg compressed_len; /* total bit length of compressed file */
     uInt matches;       /* number of string matches in current block */
     int last_eob_len;   /* bit length of EOB code for last block */
 
 #ifdef DEBUG
-    ulg bits_sent;      /* bit length of the compressed data */
+    ulg compressed_len; /* total bit length of compressed file mod 2^32 */
+    ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
 #endif
 
     ush bi_buf;
@@ -268,7 +268,7 @@ typedef struct internal_state {
         /* in trees.c */
 void _tr_init         OF((deflate_state *s));
 int  _tr_tally        OF((deflate_state *s, unsigned dist, unsigned lc));
-ulg  _tr_flush_block  OF((deflate_state *s, charf *buf, ulg stored_len,
+void _tr_flush_block  OF((deflate_state *s, charf *buf, ulg stored_len,
 			  int eof));
 void _tr_align        OF((deflate_state *s));
 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
diff --git a/lib/libz/example.c b/lib/libz/example.c
index e313c552d581..ed718cbe5f5b 100644
--- a/lib/libz/example.c
+++ b/lib/libz/example.c
@@ -3,7 +3,7 @@
  * For conditions of distribution and use, see copyright notice in zlib.h 
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id: example.c,v 1.1.1.3 1999/01/10 09:46:54 peter Exp $ */
 
 #include <stdio.h>
 #include "zlib.h"
@@ -15,6 +15,12 @@
    extern void exit  OF((int));
 #endif
 
+#if defined(VMS) || defined(RISCOS)
+#  define TESTFILE "foo-gz"
+#else
+#  define TESTFILE "foo.gz"
+#endif
+
 #define CHECK_ERR(err, msg) { \
     if (err != Z_OK) { \
         fprintf(stderr, "%s error: %d\n", msg, err); \
@@ -71,7 +77,7 @@ void test_compress(compr, comprLen, uncompr, uncomprLen)
         fprintf(stderr, "bad uncompress\n");
 	exit(1);
     } else {
-        printf("uncompress(): %s\n", uncompr);
+        printf("uncompress(): %s\n", (char *)uncompr);
     }
 }
 
@@ -79,8 +85,8 @@ void test_compress(compr, comprLen, uncompr, uncomprLen)
  * Test read/write of .gz files
  */
 void test_gzio(out, in, uncompr, uncomprLen)
-    const char *out; /* output file */
-    const char *in;  /* input file */
+    const char *out; /* compressed output file */
+    const char *in;  /* compressed input file */
     Byte *uncompr;
     int  uncomprLen;
 {
@@ -121,13 +127,13 @@ void test_gzio(out, in, uncompr, uncomprLen)
         fprintf(stderr, "bad gzread: %s\n", (char*)uncompr);
 	exit(1);
     } else {
-        printf("gzread(): %s\n", uncompr);
+        printf("gzread(): %s\n", (char *)uncompr);
     }
 
     pos = gzseek(file, -8L, SEEK_CUR);
     if (pos != 6 || gztell(file) != pos) {
 	fprintf(stderr, "gzseek error, pos=%ld, gztell=%ld\n",
-		pos, gztell(file));
+		(long)pos, (long)gztell(file));
 	exit(1);
     }
 
@@ -146,7 +152,7 @@ void test_gzio(out, in, uncompr, uncomprLen)
         fprintf(stderr, "bad gzgets after gzseek\n");
 	exit(1);
     } else {
-        printf("gzgets() after gzseek: %s\n", uncompr);
+        printf("gzgets() after gzseek: %s\n", (char *)uncompr);
     }
 
     gzclose(file);
@@ -227,7 +233,7 @@ void test_inflate(compr, comprLen, uncompr, uncomprLen)
         fprintf(stderr, "bad inflate\n");
 	exit(1);
     } else {
-        printf("inflate(): %s\n", uncompr);
+        printf("inflate(): %s\n", (char *)uncompr);
     }
 }
 
@@ -406,7 +412,7 @@ void test_sync(compr, comprLen, uncompr, uncomprLen)
     err = inflateEnd(&d_stream);
     CHECK_ERR(err, "inflateEnd");
 
-    printf("after inflateSync(): hel%s\n", uncompr);
+    printf("after inflateSync(): hel%s\n", (char *)uncompr);
 }
 
 /* ===========================================================================
@@ -492,7 +498,7 @@ void test_dict_inflate(compr, comprLen, uncompr, uncomprLen)
         fprintf(stderr, "bad inflate with dict\n");
 	exit(1);
     } else {
-        printf("inflate with dictionary: %s\n", uncompr);
+        printf("inflate with dictionary: %s\n", (char *)uncompr);
     }
 }
 
@@ -528,8 +534,8 @@ int main(argc, argv)
     }
     test_compress(compr, comprLen, uncompr, uncomprLen);
 
-    test_gzio((argc > 1 ? argv[1] : "foo.gz"),
-              (argc > 2 ? argv[2] : "foo.gz"),
+    test_gzio((argc > 1 ? argv[1] : TESTFILE),
+              (argc > 2 ? argv[2] : TESTFILE),
 	      uncompr, (int)uncomprLen);
 
     test_deflate(compr, comprLen);
diff --git a/lib/libz/gzio.c b/lib/libz/gzio.c
index e3782d582712..b2090b809480 100644
--- a/lib/libz/gzio.c
+++ b/lib/libz/gzio.c
@@ -5,7 +5,7 @@
  * Compile this file with -DNO_DEFLATE to avoid the compression code.
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id: gzio.c,v 1.1.1.3 1999/01/10 09:46:54 peter Exp $ */
 
 #include <stdio.h>
 
@@ -13,8 +13,16 @@
 
 struct internal_state {int dummy;}; /* for buggy compilers */
 
-#define Z_BUFSIZE       16384
-#define Z_PRINTF_BUFSIZE 4096
+#ifndef Z_BUFSIZE
+#  ifdef MAXSEG_64K
+#    define Z_BUFSIZE 4096 /* minimize memory usage for 16-bit DOS */
+#  else
+#    define Z_BUFSIZE 16384
+#  endif
+#endif
+#ifndef Z_PRINTF_BUFSIZE
+#  define Z_PRINTF_BUFSIZE 4096
+#endif
 
 #define ALLOC(size) malloc(size)
 #define TRYFREE(p) {if (p) free(p);}
@@ -132,8 +140,12 @@ local gzFile gz_open (path, mode, fd)
         s->stream.next_in  = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE);
 
         err = inflateInit2(&(s->stream), -MAX_WBITS);
-        /* windowBits is passed < 0 to tell that there is no zlib header */
-
+        /* windowBits is passed < 0 to tell that there is no zlib header.
+         * Note that in this case inflate *requires* an extra "dummy" byte
+         * after the compressed stream in order to complete decompression and
+         * return Z_STREAM_END. Here the gzip CRC32 ensures that 4 bytes are
+         * present after the compressed stream.
+         */
         if (err != Z_OK || s->inbuf == Z_NULL) {
             return destroy(s), (gzFile)Z_NULL;
         }
@@ -379,6 +391,7 @@ int ZEXPORT gzread (file, buf, len)
 	    len -= s->stream.avail_out;
 	    s->stream.total_in  += (uLong)len;
 	    s->stream.total_out += (uLong)len;
+            if (len == 0) s->z_eof = 1;
 	    return (int)len;
 	}
         if (s->stream.avail_in == 0 && !s->z_eof) {
@@ -401,10 +414,14 @@ int ZEXPORT gzread (file, buf, len)
 	    s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
 	    start = s->stream.next_out;
 
-	    if (getLong(s) != s->crc || getLong(s) != s->stream.total_out) {
+	    if (getLong(s) != s->crc) {
 		s->z_err = Z_DATA_ERROR;
 	    } else {
-		/* Check for concatenated .gz files: */
+	        (void)getLong(s);
+                /* The uncompressed length returned by above getlong() may
+                 * be different from s->stream.total_out) in case of
+		 * concatenated .gz files. Check for such files:
+		 */
 		check_header(s);
 		if (s->z_err == Z_OK) {
 		    uLong total_in = s->stream.total_in;
@@ -572,7 +589,7 @@ int ZEXPORT gzputs(file, s)
     gzFile file;
     const char *s;
 {
-    return gzwrite(file, (const voidp)s, (unsigned)strlen(s));
+    return gzwrite(file, (char*)s, (unsigned)strlen(s));
 }
 
 
@@ -657,7 +674,7 @@ z_off_t ZEXPORT gzseek (file, offset, whence)
 	return -1L;
 #else
 	if (whence == SEEK_SET) {
-	    offset -= s->stream.total_out;
+	    offset -= s->stream.total_in;
 	}
 	if (offset < 0) return -1L;
 
@@ -732,6 +749,7 @@ int ZEXPORT gzrewind (file)
     s->z_eof = 0;
     s->stream.avail_in = 0;
     s->stream.next_in = s->inbuf;
+    s->crc = crc32(0L, Z_NULL, 0);
 	
     if (s->startpos == 0) { /* not a compressed file */
 	rewind(s->file);
@@ -780,7 +798,8 @@ local void putLong (file, x)
 }
 
 /* ===========================================================================
-   Reads a long in LSB order from the given gz_stream. Sets 
+   Reads a long in LSB order from the given gz_stream. Sets z_err in case
+   of error.
 */
 local uLong getLong (s)
     gz_stream *s;
diff --git a/lib/libz/minigzip.c b/lib/libz/minigzip.c
index 487632e7f1d2..180b39d2ce24 100644
--- a/lib/libz/minigzip.c
+++ b/lib/libz/minigzip.c
@@ -13,7 +13,7 @@
  * or in pipe mode.
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id: minigzip.c,v 1.1.1.3 1999/01/10 09:46:57 peter Exp $ */
 
 #include <stdio.h>
 #include "zlib.h"
@@ -48,6 +48,9 @@
 #  define GZ_SUFFIX "-gz"
 #  define fileno(file) file->__file
 #endif
+#if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
+#  include <unix.h> /* for fileno */
+#endif
 
 #ifndef WIN32 /* unlink already in stdio.h for WIN32 */
   extern int unlink OF((const char *));
diff --git a/lib/libz/trees.c b/lib/libz/trees.c
index 2497001742d3..b02b5277f48a 100644
--- a/lib/libz/trees.c
+++ b/lib/libz/trees.c
@@ -29,7 +29,7 @@
  *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id: trees.c,v 1.1.1.3 1999/01/10 09:46:57 peter Exp $ */
 
 /* #define GEN_TREES_H */
 
@@ -250,6 +250,13 @@ local void tr_static_init()
 
     if (static_init_done) return;
 
+    /* For some embedded targets, global variables are not initialized: */
+    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;
+
     /* Initialize the mapping length (0..255) -> length code (0..28) */
     length = 0;
     for (code = 0; code < LENGTH_CODES-1; code++) {
@@ -378,8 +385,6 @@ void _tr_init(s)
 {
     tr_static_init();
 
-    s->compressed_len = 0L;
-
     s->l_desc.dyn_tree = s->dyn_ltree;
     s->l_desc.stat_desc = &static_l_desc;
 
@@ -393,6 +398,7 @@ void _tr_init(s)
     s->bi_valid = 0;
     s->last_eob_len = 8; /* enough lookahead for inflate */
 #ifdef DEBUG
+    s->compressed_len = 0L;
     s->bits_sent = 0L;
 #endif
 
@@ -865,9 +871,10 @@ void _tr_stored_block(s, buf, stored_len, eof)
     int eof;          /* true if this is the last block for a file */
 {
     send_bits(s, (STORED_BLOCK<<1)+eof, 3);  /* send block type */
+#ifdef DEBUG
     s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
     s->compressed_len += (stored_len + 4) << 3;
-
+#endif
     copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
 }
 
@@ -887,7 +894,9 @@ void _tr_align(s)
 {
     send_bits(s, STATIC_TREES<<1, 3);
     send_code(s, END_BLOCK, static_ltree);
+#ifdef 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
@@ -897,7 +906,9 @@ void _tr_align(s)
     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;
@@ -905,10 +916,9 @@ void _tr_align(s)
 
 /* ===========================================================================
  * Determine the best encoding for the current block: dynamic trees, static
- * trees or store, and output the encoded block to the zip file. This function
- * returns the total compressed length for the file so far.
+ * trees or store, and output the encoded block to the zip file.
  */
-ulg _tr_flush_block(s, buf, stored_len, eof)
+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 */
@@ -955,25 +965,6 @@ ulg _tr_flush_block(s, buf, stored_len, eof)
 	opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
     }
 
-    /* If compression failed and this is the first and last block,
-     * and if the .zip file can be seeked (to rewrite the local header),
-     * the whole file is transformed into a stored file:
-     */
-#ifdef STORED_FILE_OK
-#  ifdef FORCE_STORED_FILE
-    if (eof && s->compressed_len == 0L) { /* force stored file */
-#  else
-    if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
-#  endif
-        /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
-        if (buf == (charf*)0) error ("block vanished");
-
-        copy_block(buf, (unsigned)stored_len, 0); /* without header */
-        s->compressed_len = stored_len << 3;
-        s->method = STORED;
-    } else
-#endif /* STORED_FILE_OK */
-
 #ifdef FORCE_STORED
     if (buf != (char*)0) { /* force stored block */
 #else
@@ -995,25 +986,32 @@ ulg _tr_flush_block(s, buf, stored_len, eof)
 #endif
         send_bits(s, (STATIC_TREES<<1)+eof, 3);
         compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
+#ifdef DEBUG
         s->compressed_len += 3 + s->static_len;
+#endif
     } else {
         send_bits(s, (DYN_TREES<<1)+eof, 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
         s->compressed_len += 3 + s->opt_len;
+#endif
     }
     Assert (s->compressed_len == s->bits_sent, "bad compressed size");
+    /* The above check is made mod 2^32, for files larger than 512 MB
+     * and uLong implemented on 32 bits.
+     */
     init_block(s);
 
     if (eof) {
         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));
-
-    return s->compressed_len >> 3;
 }
 
 /* ===========================================================================
diff --git a/lib/libz/uncompr.c b/lib/libz/uncompr.c
index b1bd9fc41b0f..d1033213781e 100644
--- a/lib/libz/uncompr.c
+++ b/lib/libz/uncompr.c
@@ -3,7 +3,7 @@
  * For conditions of distribution and use, see copyright notice in zlib.h 
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id$ */
 
 #include "zlib.h"
 
diff --git a/lib/libz/zconf.h b/lib/libz/zconf.h
index 5b71e4b0ad42..f06124f81b7f 100644
--- a/lib/libz/zconf.h
+++ b/lib/libz/zconf.h
@@ -3,7 +3,7 @@
  * For conditions of distribution and use, see copyright notice in zlib.h 
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id: zconf.h,v 1.1.1.3 1999/01/10 09:46:58 peter Exp $ */
 
 #ifndef _ZCONF_H
 #define _ZCONF_H
@@ -91,8 +91,8 @@
 #  define NO_DUMMY_DECL
 #endif
 
-/* Borland C incorrectly complains about missing returns: */
-#if defined(__BORLANDC__)
+/* Old Borland C incorrectly complains about missing returns: */
+#if defined(__BORLANDC__) && (__BORLANDC__ < 0x500)
 #  define NEED_DUMMY_RETURN
 #endif
 
@@ -148,7 +148,7 @@
    /* MSC small or medium model */
 #  define SMALL_MEDIUM
 #  ifdef _MSC_VER
-#    define FAR __far
+#    define FAR _far
 #  else
 #    define FAR far
 #  endif
@@ -156,42 +156,68 @@
 #if defined(__BORLANDC__) && (defined(__SMALL__) || defined(__MEDIUM__))
 #  ifndef __32BIT__
 #    define SMALL_MEDIUM
-#    define FAR __far
+#    define FAR _far
 #  endif
 #endif
 
 /* Compile with -DZLIB_DLL for Windows DLL support */
-#if (defined(_WINDOWS) || defined(WINDOWS)) && defined(ZLIB_DLL)
-#  ifdef FAR
-#    undef FAR
+#if defined(ZLIB_DLL)
+#  if defined(_WINDOWS) || defined(WINDOWS)
+#    ifdef FAR
+#      undef FAR
+#    endif
+#    include <windows.h>
+#    define ZEXPORT  WINAPI
+#    ifdef WIN32
+#      define ZEXPORTVA  WINAPIV
+#    else
+#      define ZEXPORTVA  FAR _cdecl _export
+#    endif
 #  endif
-#  include <windows.h>
-#  define ZEXPORT  WINAPI
-#  ifdef WIN32
-#    define ZEXPORTVA  WINAPIV
+#  if defined (__BORLANDC__)
+#    if (__BORLANDC__ >= 0x0500) && defined (WIN32)
+#      include <windows.h>
+#      define ZEXPORT __declspec(dllexport) WINAPI
+#      define ZEXPORTRVA __declspec(dllexport) WINAPIV
+#    else
+#      if defined (_Windows) && defined (__DLL__)
+#        define ZEXPORT _export
+#        define ZEXPORTVA _export
+#      endif
+#    endif
+#  endif
+#endif
+
+#if defined (__BEOS__)
+#  if defined (ZLIB_DLL)
+#    define ZEXTERN extern __declspec(dllexport)
 #  else
-#    define ZEXPORTVA  FAR _cdecl _export
+#    define ZEXTERN extern __declspec(dllimport)
 #  endif
-#else
-#   if defined (__BORLANDC__) && defined (_Windows) && defined (__DLL__)
-#       define ZEXPORT _export
-#       define ZEXPORTVA _export
-#   else
-#       define ZEXPORT
-#       define ZEXPORTVA
-#   endif
+#endif
+
+#ifndef ZEXPORT
+#  define ZEXPORT
+#endif
+#ifndef ZEXPORTVA
+#  define ZEXPORTVA
+#endif
+#ifndef ZEXTERN
+#  define ZEXTERN extern
 #endif
 
 #ifndef FAR
 #   define FAR
 #endif
 
+#if !defined(MACOS) && !defined(TARGET_OS_MAC)
 typedef unsigned char  Byte;  /* 8 bits */
+#endif
 typedef unsigned int   uInt;  /* 16 bits or more */
 typedef unsigned long  uLong; /* 32 bits or more */
 
-#if defined(__BORLANDC__) && defined(SMALL_MEDIUM)
-   /* Borland C/C++ ignores FAR inside typedef */
+#ifdef SMALL_MEDIUM
+   /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */
 #  define Bytef Byte FAR
 #else
    typedef Byte  FAR Bytef;
@@ -217,6 +243,7 @@ typedef uLong FAR uLongf;
 #ifndef SEEK_SET
 #  define SEEK_SET        0       /* Seek from beginning of file.  */
 #  define SEEK_CUR        1       /* Seek from current position.  */
+#  define SEEK_END        2       /* Set file pointer to EOF plus "offset" */
 #endif
 #ifndef z_off_t
 #  define  z_off_t long
diff --git a/lib/libz/zutil.c b/lib/libz/zutil.c
index 0d12b55d28b2..60340c838cb9 100644
--- a/lib/libz/zutil.c
+++ b/lib/libz/zutil.c
@@ -3,7 +3,7 @@
  * For conditions of distribution and use, see copyright notice in zlib.h 
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id: zutil.c,v 1.1.1.3 1999/01/10 09:46:59 peter Exp $ */
 
 #include "zutil.h"
 
@@ -60,7 +60,7 @@ const char * ZEXPORT zError(err)
 
 void zmemcpy(dest, source, len)
     Bytef* dest;
-    Bytef* source;
+    const Bytef* source;
     uInt  len;
 {
     if (len == 0) return;
@@ -70,8 +70,8 @@ void zmemcpy(dest, source, len)
 }
 
 int zmemcmp(s1, s2, len)
-    Bytef* s1;
-    Bytef* s2;
+    const Bytef* s1;
+    const Bytef* s2;
     uInt  len;
 {
     uInt j;
@@ -178,7 +178,7 @@ void  zcfree (voidpf opaque, voidpf ptr)
 
 #  define MY_ZCALLOC
 
-#if (!defined(_MSC_VER) || (_MSC_VER < 600))
+#if (!defined(_MSC_VER) || (_MSC_VER <= 600))
 #  define _halloc  halloc
 #  define _hfree   hfree
 #endif
diff --git a/lib/libz/zutil.h b/lib/libz/zutil.h
index 3843e0de9f2f..429339ff9846 100644
--- a/lib/libz/zutil.h
+++ b/lib/libz/zutil.h
@@ -8,7 +8,7 @@
    subject to change. Applications should only use zlib.h.
  */
 
-/* $FreeBSD$ */
+/* @(#) $Id: zutil.h,v 1.1.1.3 1999/01/10 09:46:59 peter Exp $ */
 
 #ifndef _Z_UTIL_H
 #define _Z_UTIL_H
@@ -75,7 +75,7 @@ extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
 
 #ifdef MSDOS
 #  define OS_CODE  0x00
-#  ifdef __TURBOC__
+#  if defined(__TURBOC__) || defined(__BORLANDC__)
 #    if(__STDC__ == 1) && (defined(__LARGE__) || defined(__COMPACT__))
        /* Allow compilation with ANSI keywords only enabled */
        void _Cdecl farfree( void *block );
@@ -112,13 +112,12 @@ extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
 
 #if defined(MACOS) || defined(TARGET_OS_MAC)
 #  define OS_CODE  0x07
-#  ifndef fdopen
-#    define fdopen(fd,mode) NULL /* No fdopen() */
-#  endif
-#endif
-#if defined(__MWERKS__) && !defined(fdopen)
-#  if __dest_os != __be_os && __dest_os != __win32_os
-#    define fdopen(fd,mode) NULL
+#  if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
+#    include <unix.h> /* for fdopen */
+#  else
+#    ifndef fdopen
+#      define fdopen(fd,mode) NULL /* No fdopen() */
+#    endif
 #  endif
 #endif
 
@@ -134,7 +133,7 @@ extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
 #  define fdopen(fd,mode) NULL /* No fdopen() */
 #endif
 
-#if (defined(_MSC_VER) && (_MSC_VER >= 600))
+#if (defined(_MSC_VER) && (_MSC_VER > 600))
 #  define fdopen(fd,type)  _fdopen(fd,type)
 #endif
 
@@ -182,8 +181,8 @@ extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
 #    define zmemzero(dest, len) memset(dest, 0, len)
 #  endif
 #else
-   extern void zmemcpy  OF((Bytef* dest, Bytef* source, uInt len));
-   extern int  zmemcmp  OF((Bytef* s1,   Bytef* s2, uInt len));
+   extern void zmemcpy  OF((Bytef* dest, const Bytef* source, uInt len));
+   extern int  zmemcmp  OF((const Bytef* s1, const Bytef* s2, uInt len));
    extern void zmemzero OF((Bytef* dest, uInt len));
 #endif