Fix issue 286. Ensure frame elements are invalidated by...

src/virtual-frame-ia32.cc

 // Copyright 2008 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 520 matching lines @@
     Result fresh = cgen_->allocator()->Allocate();
     ASSERT(fresh.is_valid());
     Use(fresh.reg(), new_backing_index);
     backing_reg = fresh.reg();
     __ mov(backing_reg, Operand(ebp, fp_relative(index)));
   } else {
     // The original was in a register.
     backing_reg = original.reg();
     register_locations_[backing_reg.code()] = new_backing_index;
   }
+  // Invalidate the element at index.
+  elements_[index] = FrameElement::InvalidElement();
+  // Set the new backing element.
   if (elements_[new_backing_index].is_synced()) {
     elements_[new_backing_index] =
         FrameElement::RegisterElement(backing_reg, FrameElement::SYNCED);
   } else {
     elements_[new_backing_index] =
         FrameElement::RegisterElement(backing_reg, FrameElement::NOT_SYNCED);
   }
   // Update the other copies.
   for (int i = new_backing_index + 1; i < elements_.length(); i++) {
     if (elements_[i].is_copy() && elements_[i].index() == index) {
@@ skipping 397 matching lines @@
   ASSERT(stack_pointer_ == elements_.length() - 1);
   elements_.Add(FrameElement::MemoryElement());
   stack_pointer_++;
   __ push(immediate);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal