Fix for issue #6259: also look for subclasses when checking if a typed selector applies to an eleme…

lib/compiler/implementation/universe/universe.dart

Index: lib/compiler/implementation/universe/universe.dart
===================================================================
--- lib/compiler/implementation/universe/universe.dart	(revision 14186)
+++ lib/compiler/implementation/universe/universe.dart	(working copy)
@@ -526,7 +526,21 @@
     }
 
     ClassElement self = receiverType.element;
-    if (other.implementsInterface(self) || other.isSubclassOf(self)) {
+
+    // Checks if a subclass of [superClass] implements [self]. If one
+    // is found, [element] is a candidate.
+    bool hasOneSubclassThatImplements(ClassElement superClass) {

[ahe, 2012/10/29 13:15:21]

superclass is one word.

[ngeoffray, 2012/10/29 13:35:18]

Done.

+      // [TypedSelector] are only used when compiling.
+      assert(compiler.phase == Compiler.PHASE_COMPILING);
+      Set<ClassElement> typesImplementedBySubclasses =
+          compiler.world.typesImplementedBySubclasses[superClass];

[ahe, 2012/10/29 13:15:21]

I'm concerned by the direct use of maps. Could you try to encapsulate this?

I actually think it would make sense to have this operation on universe.

[ngeoffray, 2012/10/29 13:35:18]

Done.

+      if (typesImplementedBySubclasses == null) return false;
+      return typesImplementedBySubclasses.contains(receiverType);
+    }
+
+    if (other.implementsInterface(self)
+        || other.isSubclassOf(self)
+        || hasOneSubclassThatImplements(other)) {
       return appliesUntyped(element, compiler);
     }