Fix for Issue 2878

frog/world.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.
 
 /** The one true [World]. */
 World world;
 
 /**
  * Experimental phase to enable await, only set when using the
  * await/awaitc.dart entrypoint.
@@ skipping 502 matching lines @@
     avoidHazardousMemberNames();
   }
 
   makePrivateMembersUnique(Library rootLib) {
     var usedNames = new Set<String>();
     process(lib) {
       for (var name in lib._privateMembers.getKeys()) {
         if (usedNames.contains(name)) {
           var mset = lib._privateMembers[name];
           String uniqueName = '_${lib.jsname}${mset.jsname}';
-          mset.jsname = uniqueName;
           for (var member in mset.members) {
             member._jsname = uniqueName;
           }
         } else {
           usedNames.add(name);
         }
       }
     }
 
     // Visit libraries in pre-order of imports.
     var visited = new Set<Library>();
     visit(lib) {
       if (visited.contains(lib)) return;
       visited.add(lib);
       process(lib);
       for (var import in lib.imports) {
         visit(import.library);
       }
     }
     visit(rootLib);
   }
 
   /**
    * Ensures no non-native member has a jsname conflicting with a known native
    * member jsname.
    */
   avoidHazardousMemberNames() {
-    rename(jsname) {
-      if (_hazardousMemberNames.contains(jsname)) {
-        jsname = '${jsname}\$_';
-      }
-      return jsname;
-    }
-
     for (var name in _members.getKeys()) {
       var mset = _members[name];
-      bool renamed = false;
       for (var member in mset.members) {
         if (!member.isNative ||
             (member is MethodMember && member.hasNativeBody)) {
-          String oldName = member._jsname;
-          member._jsname = rename(oldName);
-          if (member._jsname != oldName) renamed = true;
+          var jsname = member._jsname;
+          if (_hazardousMemberNames.contains(jsname)) {
+            member._jsnameRoot = jsname;
+            member._jsname = '${jsname}\$_';
+          }
         }
       }
-      // If any of the members where renamed, rename mset.
-      //
-      // If all members were renamed this makes mset.jsname consistent.  If none
-      // were renamed that means they are native methods (with names different
-      // to the Dart names), so the mset name should not be renamed to stay
-      // consistent.  If only some were renamed then the mset has no consistent
-      // calling convention, and will dispatch via a stub, so the mset name is
-      // irrelevant.
-      if (renamed) {
-        mset.jsname = rename(mset.jsname);
-      }
     }
   }
 
   findMainMethod(Library lib) {
     var main = lib.lookup('main', lib.span);
     if (main == null) {
       if (!options.checkOnly) fatal('no main method specified');
     }
     return main;
   }
@@ skipping 130 matching lines @@
 
   withTiming(String name, f()) {
     final sw = new Stopwatch();
     sw.start();
     var result = f();
     sw.stop();
     info('$name in ${sw.elapsedInMs()}msec');
     return result;
   }
 }