From: Igor Sugak <igorsugak@users.noreply.github.com>
Date: Thu, 9 Jan 2020 00:17:42 +0000 (-0800)
Subject: fix UBSAN's invalid-null-argument error in zstd_decompress.c (#1939)
X-Git-Tag: v1.4.5^2~120
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=03ffda7b88da5a37c9c31478494b8768da50a008;p=thirdparty%2Fzstd.git

fix UBSAN's invalid-null-argument error in zstd_decompress.c (#1939)
---

diff --git a/lib/decompress/zstd_decompress.c b/lib/decompress/zstd_decompress.c
index d4d42e794..9e6ab216d 100644
--- a/lib/decompress/zstd_decompress.c
+++ b/lib/decompress/zstd_decompress.c
@@ -1482,7 +1482,9 @@ size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize)
 MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     size_t const length = MIN(dstCapacity, srcSize);
-    memcpy(dst, src, length);
+    if (length > 0) {
+        memcpy(dst, src, length);
+    }
     return length;
 }