Version 3.5.6.

src/runtime.cc

 // Copyright 2011 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 11356 matching lines @@
     new_current =
         isolate->factory()->NewCatchContext(function,
                                             new_previous,
                                             name,
                                             thrown_object);
   } else if (current->IsBlockContext()) {
     Handle<SerializedScopeInfo> scope_info(
         SerializedScopeInfo::cast(current->extension()));
     new_current =
         isolate->factory()->NewBlockContext(function, new_previous, scope_info);
+    // Copy context slots.
+    int num_context_slots = scope_info->NumberOfContextSlots();
+    for (int i = Context::MIN_CONTEXT_SLOTS; i < num_context_slots; ++i) {
+      new_current->set(i, current->get(i));
+    }
   } else {
     ASSERT(current->IsWithContext());
     Handle<JSObject> extension(JSObject::cast(current->extension()));
     new_current =
         isolate->factory()->NewWithContext(function, new_previous, extension);
   }
   return scope.CloseAndEscape(new_current);
 }
 
 
@@ skipping 1518 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal