From 6d60c4d4684c2c03a43f1b8720497348cf17d357 Mon Sep 17 00:00:00 2001
From: Guy Harris <guy@alum.mit.edu>
Date: Wed, 16 Dec 2015 08:59:01 +0000
Subject: [PATCH] Revert "Make zlib API constness-aware"

This reverts commit fb0246c6fd7cd34b820558f75eb48bba6326b768.  That commit assumes that if you define Z_CONST, z_const will be defined; that is *not* the case with older versions of zlib, which don't define z_const under any circumstances.

Change-Id: I6f9b7ea18922799b1aaf94dc2c63120128f2550a
Reviewed-on: https://code.wireshark.org/review/12671
Reviewed-by: Guy Harris <guy@alum.mit.edu>
---
 epan/dissectors/packet-spdy.c | 3 +--
 epan/tvbuff_zlib.c            | 1 -
 wiretap/file_wrappers.c       | 9 ++++++---
 wiretap/wtap.c                | 4 ++++
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/epan/dissectors/packet-spdy.c b/epan/dissectors/packet-spdy.c
index 7bca0b2474..a16d4cf61d 100644
--- a/epan/dissectors/packet-spdy.c
+++ b/epan/dissectors/packet-spdy.c
@@ -42,7 +42,6 @@
 #include "packet-ssl.h"
 
 #ifdef HAVE_LIBZ
-#define ZLIB_CONST
 #include <zlib.h>
 #endif
 
@@ -962,7 +961,7 @@ static guint8* spdy_decompress_header_block(tvbuff_t *tvb,
   const guint8 *hptr = tvb_get_ptr(tvb, offset, length);
   guint8 *uncomp_block = (guint8 *)wmem_alloc(wmem_packet_scope(), DECOMPRESS_BUFSIZE);
 
-  decomp->next_in = hptr;
+  decomp->next_in = (Bytef *)hptr;
   decomp->avail_in = length;
   decomp->next_out = uncomp_block;
   decomp->avail_out = DECOMPRESS_BUFSIZE;
diff --git a/epan/tvbuff_zlib.c b/epan/tvbuff_zlib.c
index 218ff53cb2..c92a5d506d 100644
--- a/epan/tvbuff_zlib.c
+++ b/epan/tvbuff_zlib.c
@@ -28,7 +28,6 @@
 #include <string.h>
 
 #ifdef HAVE_LIBZ
-#define ZLIB_CONST
 #include <zlib.h>
 #endif
 
diff --git a/wiretap/file_wrappers.c b/wiretap/file_wrappers.c
index 07daad1d6d..5918a55f6f 100644
--- a/wiretap/file_wrappers.c
+++ b/wiretap/file_wrappers.c
@@ -48,7 +48,6 @@
 #include <wsutil/file_util.h>
 
 #ifdef HAVE_LIBZ
-#define ZLIB_CONST
 #include <zlib.h>
 #endif /* HAVE_LIBZ */
 
@@ -129,7 +128,7 @@ struct wtap_reader {
     const char *err_info;      /* additional error information string for some errors */
 
     guint avail_in;            /* number of bytes available at next_in */
-    const guint8 *next_in;     /* next input byte */
+    unsigned char *next_in;    /* next input byte */
 #ifdef HAVE_LIBZ
     /* zlib inflate stream */
     z_stream strm;             /* stream structure in-place (not a pointer) */
@@ -1673,7 +1672,7 @@ gzwfile_write(GZWFILE_T state, const void *buf, guint len)
             n = state->size - strm->avail_in;
             if (n > len)
                 n = len;
-            memcpy((Bytef *)strm->next_in + strm->avail_in, buf, n);
+            memcpy(strm->next_in + strm->avail_in, buf, n);
             strm->avail_in += n;
             state->pos += n;
             buf = (const char *)buf + n;
@@ -1689,7 +1688,11 @@ gzwfile_write(GZWFILE_T state, const void *buf, guint len)
 
         /* directly compress user buffer to file */
         strm->avail_in = len;
+#if ZLIB_CONST
         strm->next_in = (z_const Bytef *)buf;
+#else
+        strm->next_in = (Bytef *)buf;
+#endif
         state->pos += len;
         if (gz_comp(state, Z_NO_FLUSH) == -1)
             return 0;
diff --git a/wiretap/wtap.c b/wiretap/wtap.c
index c4c35e8a74..30b66cd46f 100644
--- a/wiretap/wtap.c
+++ b/wiretap/wtap.c
@@ -27,6 +27,10 @@
 #include <sys/types.h>
 #endif
 
+#ifdef HAVE_LIBZ
+#include <zlib.h>
+#endif
+
 #include "wtap-int.h"
 
 #include "file_wrappers.h"