From: Joerg Sonnenberger <joerg@bec.de>
Date: Fri, 28 Apr 2017 21:32:32 +0000 (+0200)
Subject: Short cut zero size to avoid notnull attribute for mmemove in glibc.
X-Git-Tag: v3.3.2~21
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1e660621b4b00eaf4ef7a508aedf52c5a421bd2e;p=thirdparty%2Flibarchive.git

Short cut zero size to avoid notnull attribute for mmemove in glibc.

Reported-By:	OSS-Fuzz issue 497
---

diff --git a/libarchive/archive_string.c b/libarchive/archive_string.c
index 592ead2bd..ca39c069a 100644
--- a/libarchive/archive_string.c
+++ b/libarchive/archive_string.c
@@ -200,6 +200,8 @@ static int archive_string_append_unicode(struct archive_string *,
 static struct archive_string *
 archive_string_append(struct archive_string *as, const char *p, size_t s)
 {
+	if (s == 0)
+		return (as);
 	if (archive_string_ensure(as, as->length + s + 1) == NULL)
 		return (NULL);
 	memmove(as->s + as->length, p, s);