Fixing polymer element registration when extending tag extensions

pkg/polymer/lib/src/declaration.dart

Index: pkg/polymer/lib/src/declaration.dart
diff --git a/pkg/polymer/lib/src/declaration.dart b/pkg/polymer/lib/src/declaration.dart
index 72458c85229f5c59898f7a4a4dc06ba061a2bc7b..7e6be8220decb54022c31c5223e16437a567cd80 100644
--- a/pkg/polymer/lib/src/declaration.dart
+++ b/pkg/polymer/lib/src/declaration.dart
@@ -172,7 +172,7 @@ class PolymerDeclaration extends HtmlElement {
     _shimShadowDomStyling(templateContent, name);
 
     // register our custom element
-    registerType(name, extendsTag: extendee);
+    registerType(name);
 
     // NOTE: skip in Dart because we don't have mutable global scope.
     // reference constructor in a global named by 'constructor' attribute
@@ -234,10 +234,15 @@ class PolymerDeclaration extends HtmlElement {
 
   }
 
-  void registerType(String name, {String extendsTag}) {
+  void registerType(String name) {

[Jennifer Messerly, 2013/10/22 21:41:47]

retroactive question: why don't we pass in "extendee" from the caller?

Polymer uses that in the "register" function ... if the value is unreliable, it
will be a problem up there too. I suspect either this search-up-the-chain is
unnecessary, or if it is necessary, it should happen sooner...

+    var baseTag;
+    var decl = this;
+    while (decl != null) {
+      baseTag = decl.attributes['extends'];
+      decl = decl.superDeclaration;
+    }
     // native element must be specified in extends
-    var nativeExtends = (extendsTag != null && !extendsTag.contains('-')) ?
-        extendsTag : null;
+    var nativeExtends = baseTag;

[Siggi Cherem (dart-lang), 2013/10/22 16:44:17]

nit: merge baseTag or nativeExtends to use a single variable?

     document.register(name, type, extendsTag: nativeExtends);
   }