When a snapshot is generated on a 64 bit architecture and then read into a 32 bit architecture, val…

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index ff4d497e028904dd7478c0b7ddcf670d2f81de9c..1e47f62cc3bfeb10cd823a988415d4ce3cd2f63a 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -14455,9 +14455,12 @@ RawInstance* Instance::CheckAndCanonicalize(const char** error_str) const {
   if (!CheckAndCanonicalizeFields(error_str)) {
     return Instance::null();
   }
-  Instance& result = Instance::Handle();
-  const Class& cls = Class::Handle(this->clazz());
-  Array& constants = Array::Handle(cls.constants());
+  Thread* thread = Thread::Current();
+  Zone* zone = thread->zone();
+  Isolate* isolate = thread->isolate();
+  Instance& result = Instance::Handle(zone);
+  const Class& cls = Class::Handle(zone, this->clazz());
+  Array& constants = Array::Handle(zone, cls.constants());
   const intptr_t constants_len = constants.Length();
   // Linear search to see whether this value is already present in the
   // list of canonicalized constants.
@@ -14476,7 +14479,8 @@ RawInstance* Instance::CheckAndCanonicalize(const char** error_str) const {
   // The value needs to be added to the list. Grow the list if
   // it is full.
   result ^= this->raw();
-  if (result.IsNew()) {
+  if (result.IsNew() ||
+      (result.InVMHeap() && (isolate != Dart::vm_isolate()))) {
     // Create a canonical object in old space.

[srdjan, 2015/10/05 18:06:36]

Maybe comment here briefly why this is necessary.

[siva, 2015/10/05 21:51:05]

Done.

     result ^= Object::Clone(result, Heap::kOld);
   }