From: Joerg Sonnenberger <joerg@bec.de>
Date: Sat, 29 Apr 2017 16:53:17 +0000 (+0200)
Subject: Avoid memcpy if length is zero, the source can be NULL in this case.
X-Git-Tag: v3.3.2~15
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48f36b5c45acbc4a4a04bb606b87121199077a17;p=thirdparty%2Flibarchive.git

Avoid memcpy if length is zero, the source can be NULL in this case.
---

diff --git a/libarchive/archive_read.c b/libarchive/archive_read.c
index d1fecebfd..a642a336d 100644
--- a/libarchive/archive_read.c
+++ b/libarchive/archive_read.c
@@ -881,7 +881,8 @@ archive_read_data(struct archive *_a, void *buff, size_t s)
 			len = a->read_data_remaining;
 			if (len > s)
 				len = s;
-			memcpy(dest, a->read_data_block, len);
+			if (len)
+				memcpy(dest, a->read_data_block, len);
 			s -= len;
 			a->read_data_block += len;
 			a->read_data_remaining -= len;