When canonicalize instances check if all fields are canonical. If a field is a non-canonical number…

runtime/vm/raw_object_snapshot.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bigint_operations.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/snapshot.h"
 #include "vm/symbols.h"
 #include "vm/visitor.h"
@@ skipping 1693 matching lines @@
   // When reading a full snapshot we don't need to canonicalize the object
   // as it would already be a canonical object.
   // When reading a script snapshot we need to canonicalize only those object
   // references that are objects from the core library (loaded from a
   // full snapshot). Objects that are only in the script need not be
   // canonicalized as they are already canonical.
   // When reading a message snapshot we always have to canonicalize the object.
   if ((kind != Snapshot::kFull) && RawObject::IsCanonical(tags) &&
       (RawObject::IsCreatedFromSnapshot(tags) ||
        (kind == Snapshot::kMessage))) {
-    obj ^= obj.Canonicalize();
+    obj ^= obj.CheckAndCanonicalize(NULL);
+    ASSERT(!obj.IsNull());
   }
   reader->AddBackRef(object_id, &obj, kIsDeserialized);
 
   // Set the object tags.
   obj.set_tags(tags);
 
   return obj.raw();
 }
 
 
@@ skipping 914 matching lines @@
   // Write out the class and tags information.
   writer->WriteIndexedObject(kWeakPropertyCid);
   writer->WriteIntptrValue(writer->GetObjectTags(this));
 
   // Write out all the other fields.
   writer->Write<RawObject*>(ptr()->key_);
   writer->Write<RawObject*>(ptr()->value_);
 }
 
 }  // namespace dart