From: Daniel Stenberg <daniel@haxx.se>
Date: Thu, 12 Dec 2019 09:48:57 +0000 (+0100)
Subject: altsvc: make the save function ignore NULL filenames
X-Git-Tag: curl-7_68_0~74
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5dc56eb95d1a5d9ac4c35d1ad038d98731decab2;p=thirdparty%2Fcurl.git

altsvc: make the save function ignore NULL filenames

It might happen in OOM situations. Detected bv torture tests.

Closes #4707
---

diff --git a/lib/altsvc.c b/lib/altsvc.c
index 28c9276b1b..bf869c37a5 100644
--- a/lib/altsvc.c
+++ b/lib/altsvc.c
@@ -320,8 +320,8 @@ CURLcode Curl_altsvc_save(struct altsvcinfo *altsvc, const char *file)
     /* no cache activated */
     return CURLE_OK;
 
-  if((altsvc->flags & CURLALTSVC_READONLYFILE) || !file[0])
-    /* marked as read-only or zero length file name */
+  if((altsvc->flags & CURLALTSVC_READONLYFILE) || !file || !file[0])
+    /* marked as read-only, no file or zero length file name */
     return CURLE_OK;
   out = fopen(file, FOPEN_WRITETEXT);
   if(!out)