- Change when the library being loaded is registered. Now

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 5046 matching lines @@
     }
   }
   ExpectSemicolon();
 
   // Canonicalize library URL.
   const String& canon_url = String::CheckedHandle(
       CallLibraryTagHandler(Dart_kCanonicalizeUrl, import_pos, url));
   // Lookup the library URL.
   Library& library = Library::Handle(Library::LookupLibrary(canon_url));
   if (library.IsNull()) {
+    // Create an empty library to mark that we have initiated loading of this
+    // library.
+    library = Library::New(canon_url);
+    library.Register();
     // Call the library tag handler to load the library.
     // TODO(hausner): do not load eagerly if import is deferred.
     CallLibraryTagHandler(Dart_kImportTag, import_pos, canon_url);
-    // If the library tag handler succeded without registering the
-    // library we create an empty library to import.
-    library = Library::LookupLibrary(canon_url);
-    if (library.IsNull()) {
-      library = Library::New(canon_url);
-      library.Register();
-    }
   }
 
   Namespace& ns =
       Namespace::Handle(Namespace::New(library, show_names, hide_names));
   if (metadata_pos >= 0) {
     ns.AddMetadata(metadata_pos, current_class());
   }
 
   if (is_import) {
     // Ensure that private dart:_ libraries are only imported into dart:
@@ skipping 5867 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart