Uniformly handle 'undefined' store to Float64Array and Float32Array.

src/objects.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 11739 matching lines @@
       // converted to a number type further up in the call chain.
       ASSERT(value->IsUndefined());
     }
     set(index, cast_value);
   }
   return heap->NumberFromUint32(cast_value);
 }
 
 
 MaybeObject* ExternalFloatArray::SetValue(uint32_t index, Object* value) {
-  float cast_value = 0;
+  float cast_value = OS::nan_value();
   Heap* heap = GetHeap();
   if (index < static_cast<uint32_t>(length())) {
     if (value->IsSmi()) {
       int int_value = Smi::cast(value)->value();
       cast_value = static_cast<float>(int_value);
     } else if (value->IsHeapNumber()) {
       double double_value = HeapNumber::cast(value)->value();
       cast_value = static_cast<float>(double_value);
     } else {
-      // Clamp undefined to zero (default). All other types have been
+      // Clamp undefined to NaN (default). All other types have been
       // converted to a number type further up in the call chain.
       ASSERT(value->IsUndefined());
     }
     set(index, cast_value);
   }
   return heap->AllocateHeapNumber(cast_value);
 }
 
 
 MaybeObject* ExternalDoubleArray::SetValue(uint32_t index, Object* value) {
-  double double_value = 0;
+  double double_value = OS::nan_value();
   Heap* heap = GetHeap();
   if (index < static_cast<uint32_t>(length())) {
     if (value->IsSmi()) {
       int int_value = Smi::cast(value)->value();
       double_value = static_cast<double>(int_value);
     } else if (value->IsHeapNumber()) {
       double_value = HeapNumber::cast(value)->value();
     } else {
-      // Clamp undefined to zero (default). All other types have been
+      // Clamp undefined to NaN (default). All other types have been
       // converted to a number type further up in the call chain.
       ASSERT(value->IsUndefined());
     }
     set(index, double_value);
   }
   return heap->AllocateHeapNumber(double_value);
 }
 
 
 JSGlobalPropertyCell* GlobalObject::GetPropertyCell(LookupResult* result) {
@@ skipping 1270 matching lines @@
   if (break_point_objects()->IsUndefined()) return 0;
   // Single break point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 } }  // namespace v8::internal