From: Mike Frysinger <vapier@gentoo.org>
Date: Sat, 31 Oct 2015 04:47:59 +0000 (-0400)
Subject: printflags: handle empty xlats
X-Git-Tag: v4.11~147
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=79bddff923862fbf4e4d349c714d4c3ea9d14e81;p=strace

printflags: handle empty xlats

If the set of headers are unable to produce a valid list, printflags
will try to pass NULL to tprints which crashes.  Add a sanity check
for this edge case.

* util.c (printflags): Check xlat->str is not NULL.
---

diff --git a/util.c b/util.c
index c3e3fdaf..5f1f733e 100644
--- a/util.c
+++ b/util.c
@@ -352,7 +352,7 @@ printflags(const struct xlat *xlat, int flags, const char *dflt)
 	int n;
 	const char *sep;
 
-	if (flags == 0 && xlat->val == 0) {
+	if (flags == 0 && xlat->val == 0 && xlat->str) {
 		tprints(xlat->str);
 		return 1;
 	}