Changing internal behaviour of tcmalloc to return an allocated size of 0 when the target pointer is null (refer to TCMallocImplementation::GetAllocatedSize). This change was reviewed as https://codereview.appspot.com/5833050/.

git-svn-id: http://gperftools.googlecode.com/svn/trunk@149 6b5cf1ce-ec42-a296-1ba9-69fdba395a50

src/tcmalloc.cc

@@ -1468,6 +1468,8 @@ void* cpp_memalign(size_t align, size_t size) {
 
 // As promised, the definition of this function, declared above.
 size_t TCMallocImplementation::GetAllocatedSize(const void* ptr) {
+  if (ptr == NULL)
+    return 0;
   ASSERT(TCMallocImplementation::GetOwnership(ptr)
          != TCMallocImplementation::kNotOwned);
   return GetSizeWithCallback(ptr, &InvalidGetAllocatedSize);