Fix undefined behavior in VectorImpl

Summary: memcpy on null operands is undefined, add a test. Reviewed By: yuxuanchen1997 Differential Revision: D18075640 fbshipit-source-id: cb1380d5130e102c2ca09bd343ebed9335a3190a
leiiiooo · Oct 24, 2019 · 489a085 · 489a085
1 parent 7f70006
commit 489a085
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/libresource/VectorImpl.cpp b/libresource/VectorImpl.cpp
@@ -124,6 +124,9 @@ ssize_t VectorImpl::insertArrayAt(const void* array, size_t index, size_t length
 {
     if (index > size())
         return BAD_INDEX;
+    if (!length) {
+      return index;
+    }
     void* where = _grow(index, length);
     if (where) {
         _do_copy(where, array, length);
@@ -640,4 +643,3 @@ ssize_t SortedVectorImpl::remove(const void* item)
 /*****************************************************************************/
 
 }; // namespace android
-