Fix named parameters handling of values that are falsy in JS.

compiler/java/com/google/dart/compiler/util/AstUtil.java

Index: compiler/java/com/google/dart/compiler/util/AstUtil.java
===================================================================
--- compiler/java/com/google/dart/compiler/util/AstUtil.java	(revision 305)
+++ compiler/java/com/google/dart/compiler/util/AstUtil.java	(working copy)
@@ -66,11 +66,21 @@
     return nameRef;
   }
 
-  public static JsNameRef newNameRef(JsExpression qualifier, JsName prop) {
+  public static JsNameRef nameref(SourceInfo info, JsName qualifier, JsName prop) {
     JsNameRef nameRef = new JsNameRef(prop);
     if (qualifier != null) {
+      nameRef.setQualifier(qualifier.makeRef());
+    }
+    nameRef.setSourceRef(info);
+    return nameRef;
+  }
+
+  public static JsNameRef nameref(SourceInfo info, JsExpression qualifier, JsName prop) {

[jat, 2011/10/11 20:28:23]

Since newNameRef is going away, I suggest either leaving the rename of
newNameRef->nameRef to a separate CL that does all of them, or do all of them
now.

[John Lenz, 2011/10/11 20:35:55]

Done.

+    JsNameRef nameRef = new JsNameRef(prop);
+    if (qualifier != null) {
       nameRef.setQualifier(qualifier);
     }
+    nameRef.setSourceRef(info);
     return nameRef;
   }
 
@@ -174,8 +184,9 @@
     return (JsInvocation) newInvocation(target, params).setSourceRef(src);
   }
 
-  public static JsExpression comma(SourceInfo src, JsExpression op1, JsExpression op2) {
-    return new JsBinaryOperation(JsBinaryOperator.COMMA, op1, op2).setSourceRef(src);
+  public static JsBinaryOperation comma(SourceInfo src, JsExpression op1, JsExpression op2) {
+    return (JsBinaryOperation)new JsBinaryOperation(JsBinaryOperator.COMMA, op1, op2)
+       .setSourceRef(src);
   }
 
   public static JsNameRef nameref(SourceInfo src, String name) {
@@ -205,4 +216,8 @@
   public static JsExpression and(SourceInfo src, JsExpression op1, JsExpression op2) {
     return new JsBinaryOperation(JsBinaryOperator.AND, op1, op2);
   }
+
+  public static JsExpression in(SourceInfo src, JsExpression op1, JsExpression op2) {

[jat, 2011/10/11 20:28:23]

op1 and op2 could have more useful names, perhaps key and map?

[John Lenz, 2011/10/11 20:35:55]

used "propName" and "obj"

+    return new JsBinaryOperation(JsBinaryOperator.INOP, op1, op2).setSourceRef(src);
+  }
 }