From: Mark Adler <madler@alumni.caltech.edu>
Date: Tue, 27 Dec 2022 07:36:01 +0000 (-0800)
Subject: Fix crash when gzsetparams() attempted for transparent write.
X-Git-Tag: 2.1.0-beta1~78
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e713f2f460a1b7fcf617ae837bc95b68abb3803b;p=thirdparty%2Fzlib-ng.git

Fix crash when gzsetparams() attempted for transparent write.

gzsetparams() now returns a Z_STREAM_ERROR in this case.
---

diff --git a/gzwrite.c b/gzwrite.c
index ba716bc20..08e0ce9aa 100644
--- a/gzwrite.c
+++ b/gzwrite.c
@@ -460,7 +460,7 @@ int Z_EXPORT PREFIX(gzsetparams)(gzFile file, int level, int strategy) {
     strm = &(state->strm);
 
     /* check that we're writing and that there's no error */
-    if (state->mode != GZ_WRITE || state->err != Z_OK)
+    if (state->mode != GZ_WRITE || state->err != Z_OK || state->direct)
         return Z_STREAM_ERROR;
 
     /* if no change is requested, then do nothing */