Avoid SLOW_ASSERT when calling HeapGraphNode::GetChildrenCount

src/heap-snapshot-generator-inl.h

 // Copyright 2013 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 41 matching lines @@
 int HeapEntry::set_children_index(int index) {
   children_index_ = index;
   int next_index = index + children_count_;
   children_count_ = 0;
   return next_index;
 }
 
 
 HeapGraphEdge** HeapEntry::children_arr() {
   ASSERT(children_index_ >= 0);
-  return &snapshot_->children()[children_index_];
+  SLOW_ASSERT(children_index_ < snapshot_->children().length() ||
+      (children_index_ == snapshot_->children().length() &&
+       children_count_ == 0));
+  return &snapshot_->children().first() + children_index_;

[alph, 2013/12/18 15:15:51]

first -> start

[yurys, 2013/12/18 15:19:27]

List doesn't have start(), you may have confused it with Vector::start().

 }
 
 
 SnapshotObjectId HeapObjectsMap::GetNthGcSubrootId(int delta) {
   return kGcRootsFirstSubrootId + delta * kObjectIdStep;
 }
 
 
 HeapObject* V8HeapExplorer::GetNthGcSubrootObject(int delta) {
   return reinterpret_cast<HeapObject*>(
       reinterpret_cast<char*>(kFirstGcSubrootObject) +
       delta * HeapObjectsMap::kObjectIdStep);
 }
 
 
 int V8HeapExplorer::GetGcSubrootOrder(HeapObject* subroot) {
   return static_cast<int>(
       (reinterpret_cast<char*>(subroot) -
        reinterpret_cast<char*>(kFirstGcSubrootObject)) /
       HeapObjectsMap::kObjectIdStep);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_SNAPSHOT_GENERATOR_INL_H_