fortify-headers

commit a255506ca487250255f9f048e61cf90166ceab77
parent 7fd984fcb532be01f68cddc194c09a7ca10c1ea6
Author: sin <sin@2f30.org>
Date:   Wed, 15 Jul 2015 15:53:41 +0100

Fix wcrtomb() check

This was breaking valid code, example:
char c;
wcrtomb(&c, L'0', st);

Diffstat:
M
include/wchar.h
 | 
15
+++++++++++++--

1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/include/wchar.h b/include/wchar.h
@@ -17,8 +17,12 @@
 #define _FORTIFY_WCHAR_H
 
 __extension__
+#include_next <limits.h>
+__extension__
 #include_next <stdlib.h>
 __extension__
+#include_next <string.h>
+__extension__
 #include_next <wchar.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
@@ -99,10 +103,17 @@ _FORTIFY_FN(mbstowcs) size_t mbstowcs(wchar_t *__ws, const char *__s, size_t __w
 
 _FORTIFY_FN(wcrtomb) size_t wcrtomb(char *__s, wchar_t __w, mbstate_t *__st)
 {
+	char __buf[MB_LEN_MAX];
 	size_t __b = __builtin_object_size(__s, 0);
+	size_t __r;
 
-	if (__s && MB_CUR_MAX > __b)
-		__builtin_trap();
+	if (__s) {
+		__r = __orig_wcrtomb(__buf, __w, __st);
+		if (__r > __b)
+			__builtin_trap();
+		memcpy(__s, __buf, __r);
+		return __r;
+	}
 	return __orig_wcrtomb(__s, __w, __st);
 }