From: Rich Felker <dalias@aerifal.cx>
Date: Thu, 29 Sep 2011 02:07:58 +0000 (-0400)
Subject: don't crash on null strings in printf
X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=commitdiff_plain;h=5f814682b48c59f07568d349f979eed4cf306703

don't crash on null strings in printf

passing null pointer for %s is UB but lots of broken programs do it anyway
---

diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index 4c990e5e..b5001ff2 100644
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c
@@ -584,7 +584,7 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 		case 'm':
 			if (1) a = strerror(errno); else
 		case 's':
-			a = arg.p;
+			a = arg.p ? arg.p : "(null)";
 			z = memchr(a, 0, p);
 			if (!z) z=a+p;
 			else p=z-a;