Made dart2js constructor lookup logic "private"-aware, fixed 4740 bug.

lib/compiler/implementation/elements/elements.dart

Index: lib/compiler/implementation/elements/elements.dart
diff --git a/lib/compiler/implementation/elements/elements.dart b/lib/compiler/implementation/elements/elements.dart
index cebff15544db0b379fcb92675f348e861fb6ebf5..9d49db35b70956ee7adcb30e8075630f35493e25 100644
--- a/lib/compiler/implementation/elements/elements.dart
+++ b/lib/compiler/implementation/elements/elements.dart
@@ -1403,21 +1403,14 @@ abstract class ClassElement extends ScopeContainerElement
     }
   }
 
-  Element lookupConstructor(SourceString className,
-                            [SourceString constructorName =
-                                 const SourceString(''),
-                            Element noMatch(Element)]) {
+  Element lookupConstructor(Selector selector, [Element noMatch(Element)]) {
     // TODO(karlklose): have a map from class names to a map of constructors
     //                  instead of creating the name here?
-    SourceString normalizedName;
-    if (constructorName !== const SourceString('')) {
-      normalizedName = Elements.constructConstructorName(className,
-                                                         constructorName);
-    } else {
-      normalizedName = className;
-    }
-    Element result = localLookup(normalizedName);
-    if (result === null || !result.isConstructor()) {
+    Element result = localLookup(selector.normalizedConstructorName);

[kasperl, 2012/10/08 08:06:41]

Can't you construct the normalized constructor name here from the class name in
[this] ClassElement and the name in the selector? Alternatively, you should
implement your own variant of localLookup that runs through local constructors
(guaranteed to be on the right class) and see if the name in the selector
matches?

[aam-me, 2012/10/09 04:08:42]

Thanks for the tips. I gave it a try.

+    if (result === null
+        || !result.isConstructor()
+        || (selector.name.isPrivate()
+            && result.getLibrary() != selector.library)) {
       result = noMatch !== null ? noMatch(result) : null;
     }
     return result;