Avoid passing a null uri to translateUri.

lib/compiler/implementation/apiimpl.dart

 // 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.
 
 #library('leg_apiimpl');
 
 #import('dart:uri');
 
 #import('../compiler.dart', prefix: 'api');
 #import('leg.dart', prefix: 'leg');
@@ skipping 78 matching lines @@
 
   bool run(Uri uri) {
     bool success = super.run(uri);
     for (final task in tasks) {
       log('${task.name} took ${task.timing}msec');
     }
     return success;
   }
 
   void reportDiagnostic(leg.SourceSpan span, String message, bool fatal) {
-    if (span === null) {
+    if (span === null || span.uri === null) {

[ahe, 2012/06/22 08:49:33]

I would rather avoid creating source spans with uri == null. It is done in a few
places and should be easy to change to using null.

[Johnni Winther, 2012/06/22 11:40:55]

Done.

       handler(null, null, null, message, fatal);
     } else {
       handler(translateUri(span.uri, null), span.begin, span.end,
               message, fatal);
     }
   }
 
   bool get isMockCompilation() {
     return mockableLibraryUsed
       && (options.indexOf('--allow-mock-compilation') !== -1);
   }
 }