check copy has different address. If same, skip the copy to avoid valgrind error.

BUG=334
TESTED=unittests still pass
R=tpsiaki@google.com

Review URL: https://webrtc-codereview.appspot.com/14679004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1011 16f28f9a-4ce2-e073-06de-1de4eb20be90

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 1010
+Version: 1011
 License: BSD
 License File: LICENSE
 

include/libyuv/version.h

@@ -11,6 +11,6 @@
 #ifndef INCLUDE_LIBYUV_VERSION_H_  // NOLINT
 #define INCLUDE_LIBYUV_VERSION_H_
 
-#define LIBYUV_VERSION 1010
+#define LIBYUV_VERSION 1011
 
 #endif  // INCLUDE_LIBYUV_VERSION_H_  NOLINT

source/planar_functions.cc

@@ -37,6 +37,10 @@ void CopyPlane(const uint8* src_y, int src_stride_y,
     height = 1;
     src_stride_y = dst_stride_y = 0;
   }
+  // Nothing to do.
+  if (src_y == dst_y && src_stride_y == dst_stride_y) {
+    return;
+  }
 #if defined(HAS_COPYROW_X86)
   if (TestCpuFlag(kCpuHasX86) && IS_ALIGNED(width, 4)) {
     CopyRow = CopyRow_X86;