Temporary fix for pub crash by canonicalizing type only if the IsCreatedFromSnapshot bit is true (i…

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/object.h"
 #include "vm/object_store.h"
 #include "vm/snapshot.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 #include "vm/visitor.h"
@@ skipping 192 matching lines @@
 
 RawType* Type::ReadFrom(SnapshotReader* reader,
                         intptr_t object_id,
                         intptr_t tags,
                         Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Allocate type object.
   Type& type = Type::ZoneHandle(reader->zone(), NEW_OBJECT(Type));
   bool is_canonical = RawObject::IsCanonical(tags);
-  bool defer_canonicalization = is_canonical && (kind != Snapshot::kFull);
+  bool defer_canonicalization = is_canonical &&
+      ((kind == Snapshot::kScript && RawObject::IsCreatedFromSnapshot(tags)) ||
+       kind == Snapshot::kMessage);
   reader->AddBackRef(object_id, &type, kIsDeserialized, defer_canonicalization);
 
   // Set all non object fields.
   type.set_token_pos(reader->Read<int32_t>());
   type.set_type_state(reader->Read<int8_t>());
 
   // Set all the object fields.
   // TODO(5411462): Need to assert No GC can happen here, even though
   // allocations may happen.
   intptr_t num_flds = (type.raw()->to() - type.raw()->from());
@@ skipping 220 matching lines @@
                                           intptr_t tags,
                                           Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Read the length so that we can determine instance size to allocate.
   intptr_t len = reader->ReadSmiValue();
 
   TypeArguments& type_arguments = TypeArguments::ZoneHandle(
       reader->zone(), NEW_OBJECT_WITH_LEN_SPACE(TypeArguments, len, kind));
   bool is_canonical = RawObject::IsCanonical(tags);
-  bool defer_canonicalization = is_canonical && (kind != Snapshot::kFull);
+  bool defer_canonicalization = is_canonical &&
+      ((kind == Snapshot::kScript && RawObject::IsCreatedFromSnapshot(tags)) ||
+       kind == Snapshot::kMessage);
   reader->AddBackRef(object_id,
                      &type_arguments,
                      kIsDeserialized,
                      defer_canonicalization);
 
   // Set the instantiations field, which is only read from a full snapshot.
   if (kind == Snapshot::kFull) {
     *(reader->ArrayHandle()) ^= reader->ReadObjectImpl(kAsInlinedObject);
     type_arguments.set_instantiations(*(reader->ArrayHandle()));
   } else {
@@ skipping 2633 matching lines @@
     // We do not allow objects with native fields in an isolate message.
     writer->SetWriteException(Exceptions::kArgument,
                               "Illegal argument in isolate message"
                               " : (object is a UserTag)");
   } else {
     UNREACHABLE();
   }
 }
 
 }  // namespace dart