Merge pull request #45 from wthie/athenaDetachClient-fix-12

Avoid missing children due to array modification during iteration while detaching widgets. Author: wthie Reviewer: mithrandi
twisted · Aug 12, 2014 · 8dd62fa · 8dd62fa
2 parents b4a483d + e62cd13
commit 8dd62fa
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Showing 3 changed files with 15 additions and 8 deletions.
diff --git a/nevow/athena.py b/nevow/athena.py
@@ -1804,7 +1804,7 @@ def _athenaDetachServer(self):
         """
         if self.fragmentParent is None:
             raise OrphanedFragment(self)
-        for ch in self.liveFragmentChildren:
+        for ch in list(self.liveFragmentChildren):
             ch._athenaDetachServer()
         self.fragmentParent.liveFragmentChildren.remove(self)
         self.fragmentParent = None

diff --git a/nevow/js/Nevow/Athena/Tests/__init__.js b/nevow/js/Nevow/Athena/Tests/__init__.js
@@ -755,27 +755,31 @@ Nevow.Athena.Tests.DynamicWidgetInstantiation.methods(
 
     function _testDetachWithChildren(self, detach) {
         var parent = null;
-        var child = null;
-        var result = self.callRemote('getAndSaveDynamicWidgetWithChild');
+        var child0 = null;
+        var child1 = null;
+        var result = self.callRemote('getAndSaveDynamicWidgetWithChildren');
         result.addCallback(
             function(widgetInfo) {
                 return self.addChildWidgetFromWidgetInfo(widgetInfo);
             });
         result.addCallback(
             function(widget) {
                 parent = widget;
-                child = widget.childWidgets[0];
+                child0 = widget.childWidgets[0];
+                child1 = widget.childWidgets[1];
                 return widget.detach();
             });
         result.addCallback(
             function(ignored) {
                 self.assertEqual(parent.childWidgets.length, 0);
                 self.assertEqual(parent.widgetParent, null);
-                self.assertEqual(child.widgetParent, null);
+                self.assertEqual(child0.widgetParent, null);
+                self.assertEqual(child1.widgetParent, null);
 
                 var widgets = Nevow.Athena.Widget._athenaWidgets;
                 self.failIf(parent.objectID in widgets);
-                self.failIf(child.objectID in widgets);
+                self.failIf(child0.objectID in widgets);
+                self.failIf(child1.objectID in widgets);
             });
         return result;
     },

diff --git a/nevow/js/Nevow/Athena/__init__.js b/nevow/js/Nevow/Athena/__init__.js
@@ -1127,8 +1127,11 @@ Nevow.Athena.Widget.methods(
      * tracking system.
      */
     function _athenaDetachClient(self) {
-        for (var i = 0; i < self.childWidgets.length; ++i) {
-            self.childWidgets[i]._athenaDetachClient();
+        //copy of self.childWidgets for safe iteration by removeChildWidget
+        var childWidgets = self.childWidgets.slice();
+
+        for (var i = 0; i < childWidgets.length; ++i) {
+            childWidgets[i]._athenaDetachClient();
         }
         if (self.widgetParent !== null) {
             self.widgetParent.removeChildWidget(self);