From: Pierre Ossman <ossman@cendio.se>
Date: Thu, 27 Feb 2020 12:35:41 +0000 (+0100)
Subject: Fix error check for zlib calls
X-Git-Tag: v1.10.90~47
X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=1688e8cd57606f7aaeb0abddc8e9ce3827d253cc;p=tigervnc.git

Fix error check for zlib calls

There are multiple "okay" return values, not just Z_OK. Make sure we
don't bail out needlessly.
---

diff --git a/common/rdr/ZlibInStream.cxx b/common/rdr/ZlibInStream.cxx
index 9fcfaf6b..0fb3ad1e 100644
--- a/common/rdr/ZlibInStream.cxx
+++ b/common/rdr/ZlibInStream.cxx
@@ -141,7 +141,7 @@ bool ZlibInStream::decompress(bool wait)
     zs->avail_in = bytesIn;
 
   int rc = inflate(zs, Z_SYNC_FLUSH);
-  if (rc != Z_OK) {
+  if (rc < 0) {
     throw Exception("ZlibInStream: inflate failed");
   }
 
diff --git a/common/rdr/ZlibOutStream.cxx b/common/rdr/ZlibOutStream.cxx
index 7a0d692c..99d0617a 100644
--- a/common/rdr/ZlibOutStream.cxx
+++ b/common/rdr/ZlibOutStream.cxx
@@ -159,7 +159,7 @@ void ZlibOutStream::deflate(int flush)
 #endif
 
     rc = ::deflate(zs, flush);
-    if (rc != Z_OK) {
+    if (rc < 0) {
       // Silly zlib returns an error if you try to flush something twice
       if ((rc == Z_BUF_ERROR) && (flush != Z_NO_FLUSH))
         break;
@@ -193,7 +193,7 @@ void ZlibOutStream::checkCompressionLevel()
     deflate(Z_SYNC_FLUSH);
 
     rc = deflateParams (zs, newLevel, Z_DEFAULT_STRATEGY);
-    if (rc != Z_OK) {
+    if (rc < 0) {
       // The implicit flush can result in this error, caused by the
       // explicit flush we did above. It should be safe to ignore though
       // as the first flush should have left things in a stable state...