Fix VM crash when parsing what looks like a closure call during metadata evaluation.

runtime/vm/parser.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/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
@@ skipping 7645 matching lines @@
 
 
 void Parser::EnsureExpressionTemp() {
   // Temporary used later by the flow_graph_builder.
   parsed_function()->EnsureExpressionTemp();
 }
 
 
 void Parser::EnsureSavedCurrentContext() {
   // Used later by the flow_graph_builder to save current context.
+  if (parsing_metadata_) {
+    return;

[hausner, 2014/02/27 18:53:22]

Can you please explain in a comment why it is necessary to return here when
parsing metadata, any why that is ok? Why do we not need to save the current
context?

[rmacnak, 2014/02/27 19:11:27]

Hm, actually this is dubious because it relies on the expression being noticed
as non-const later on. Hoisted the check to ParseSelectors so it fails early
with a more intention-revealing error message.

+  }
   if (!parsed_function()->has_saved_current_context_var()) {
     LocalVariable* temp =
         new LocalVariable(current_function().token_pos(),
                           Symbols::SavedCurrentContextVar(),
                           Type::ZoneHandle(Type::DynamicType()));
     ASSERT(temp != NULL);
     parsed_function()->set_saved_current_context_var(temp);
   }
 }
 
@@ skipping 3102 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart