Add missing length check when copying fixed arrays.

src/heap-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_INL_H_
 #define V8_HEAP_INL_H_
 
 #include <cmath>
 
 #include "heap.h"
@@ skipping 143 matching lines @@
   ASSERT_EQ(size, answer->Size());
 
   // Fill in the characters.
   OS::MemCopy(answer->address() + SeqTwoByteString::kHeaderSize,
               str.start(), str.length() * kUC16Size);
 
   return answer;
 }
 
 MaybeObject* Heap::CopyFixedArray(FixedArray* src) {
+  if (src->length() == 0) return src;
   return CopyFixedArrayWithMap(src, src->map());
 }
 
 
 MaybeObject* Heap::CopyFixedDoubleArray(FixedDoubleArray* src) {
+  if (src->length() == 0) return src;
   return CopyFixedDoubleArrayWithMap(src, src->map());
 }
 
 
 MaybeObject* Heap::CopyConstantPoolArray(ConstantPoolArray* src) {
+  if (src->length() == 0) return src;
   return CopyConstantPoolArrayWithMap(src, src->map());
 }
 
 
 MaybeObject* Heap::AllocateRaw(int size_in_bytes,
                                AllocationSpace space,
                                AllocationSpace retry_space) {
   ASSERT(AllowHandleAllocation::IsAllowed());
   ASSERT(AllowHeapAllocation::IsAllowed());
   ASSERT(gc_state_ == NOT_IN_GC);
@@ skipping 590 matching lines @@
 
 
 double GCTracer::SizeOfHeapObjects() {
   return (static_cast<double>(heap_->SizeOfObjects())) / MB;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_INL_H_