Fix bug in compilation-handlescope.

src/api.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 6439 matching lines @@
     Object** block_limit = &block_start[kHandleBlockSize];
     // We should not need to check for NoHandleAllocation here. Assert
     // this.
     ASSERT(prev_limit == block_limit ||
            !(block_start <= prev_limit && prev_limit <= block_limit));
     if (prev_limit == block_limit) break;
     deferred->blocks_.Add(blocks_.last());
     blocks_.RemoveLast();
   }
 
+  // deferred->blocks_ now contains the blocks installed on the
+  // HandleScope stack since BeginDeferredScope was called, but in
+  // reverse order.
+
+  ASSERT(prev_limit == NULL || !blocks_.is_empty());
+
   ASSERT(!blocks_.is_empty() && prev_limit != NULL);
   deferred_handles_head_ = deferred;
   ASSERT(last_handle_before_deferred_block_ != NULL);
   last_handle_before_deferred_block_ = NULL;
   return deferred;
 }
 
 
 void HandleScopeImplementer::DestroyDeferredHandles(DeferredHandles* deferred) {
+#ifdef DEBUG
+  DeferredHandles* deferred_iterator = deferred;
+  while (deferred_iterator->previous_ != NULL) {
+    deferred_iterator = deferred_iterator->previous_;
+  }
+  ASSERT(deferred_handles_head_ == deferred_iterator);
+#endif
   if (deferred_handles_head_ == deferred) {
     deferred_handles_head_ = deferred_handles_head_->next_;
   }
   if (deferred->next_ != NULL) {
     deferred->next_->previous_ = deferred->previous_;
   }
   if (deferred->previous_ != NULL) {
     deferred->previous_->next_ = deferred->next_;
   }
   for (int i = 0; i < deferred->blocks_.length(); i++) {
@@ skipping 14 matching lines @@
 
 
 DeferredHandles::~DeferredHandles() {
   impl_->DestroyDeferredHandles(this);
 }
 
 
 void DeferredHandles::Iterate(ObjectVisitor* v) {
   ASSERT(!blocks_.is_empty());
 
-  for (int i = 0; i < (blocks_.length() - 1); i++) {
+  ASSERT((first_block_limit_ >= blocks_.first()) &&
+         (first_block_limit_ < &(blocks_.first())[kHandleBlockSize]));
+
+  v->VisitPointers(blocks_.first(), first_block_limit_);
+
+  for (int i = 1; i < blocks_.length(); i++) {
     v->VisitPointers(blocks_[i], &blocks_[i][kHandleBlockSize]);
   }
-
-  ASSERT((last_block_limit_ >= blocks_.last()) &&
-         (last_block_limit_ < &(blocks_.last())[kHandleBlockSize]));
-
-  v->VisitPointers(blocks_.last(), last_block_limit_);
 }
 
 
 } }  // namespace v8::internal