Fix for issue 20045.

runtime/vm/object.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 "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 16975 matching lines @@
         memmove(array,
                 TwoByteString::CharAddr(*this, 0),
                 (str_length * kTwoByteChar));
       }
 
       // Update the class information of the object.
       const intptr_t class_id = kExternalTwoByteStringCid;
       tags = RawObject::SizeTag::update(used_size, tags);
       tags = RawObject::ClassIdTag::update(class_id, tags);
       raw_ptr()->tags_ = tags;
-      const String& result = String::Handle(this->raw());
+      result = this->raw();
       ExternalStringData<uint16_t>* ext_data = new ExternalStringData<uint16_t>(
           reinterpret_cast<const uint16_t*>(array), peer, cback);
       result.SetLength(str_length);
       result.SetHash(0);
       ExternalTwoByteString::SetExternalData(result, ext_data);
       external_data = ext_data;
       finalizer = ExternalTwoByteString::Finalize;
     }
 
     // If there is any left over space fill it with either an Array object or
@@ skipping 2158 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart