From e2c32e9f966cf9f2c9ed94bf0703344a2cca284b Mon Sep 17 00:00:00 2001
From: Andreas Huber <andih@google.com>
Date: Mon, 21 Mar 2011 14:16:03 -0700
Subject: [PATCH] If nothing is to be copied, return right away.

This avoids a potential out-of-bounds problem in the code below.

Change-Id: I942d55da0a5288b37512cb74407f900a2d824c0c
related-to-bug: 4139974
---
 media/libstagefright/NuCachedSource2.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/media/libstagefright/NuCachedSource2.cpp b/media/libstagefright/NuCachedSource2.cpp
index c7b99b9bf4bf2..248b67806c36d 100644
--- a/media/libstagefright/NuCachedSource2.cpp
+++ b/media/libstagefright/NuCachedSource2.cpp
@@ -135,6 +135,10 @@ size_t PageCache::releaseFromStart(size_t maxBytes) {
 void PageCache::copy(size_t from, void *data, size_t size) {
     LOGV("copy from %d size %d", from, size);
 
+    if (size == 0) {
+        return;
+    }
+
     CHECK_LE(from + size, mTotalSize);
 
     size_t offset = 0;