Can't reproduce reliably. Happens when you edit, delete inside indented blips and then try to add a new indented blip in the conversation.

Stack trace:

Token: 1303112570144 One or more exceptions caught, see full set in UmbrellaException#getCauses Unknown.$fillInStackTrace (StackTraceCreator.java:147) Unknown.fillInStackTrace (StackTraceCreator.java:387) Unknown.RuntimeException_2 (Throwable.java:46) Unknown.UmbrellaException_0 (com.google.gwt.dev.jjs.ast.JProgram:0) Unknown.$doFire (SimpleEventBus.java:214) Unknown.$fireEvent_0 (SimpleEventBus.java:103) Unknown.$fireEvent (HandlerManager.java:101) Unknown.$fireEvent_1 (Widget.java:103) Unknown.fireNativeEvent (DomEvent.java:116) Unknown.$onBrowserEvent (Widget.java:151) Unknown.onBrowserEvent (Widget.java:137) Unknown.dispatchEvent_1 (DOM.java:1264) Unknown.anonymous (DOMImplStandard.java:187) Unknown.entry0 (Impl.java:214) Unknown.anonymous (Impl.java:57) Caused by: Token: 1303112570152 (TypeError): Cannot read property 'next' of null stack: TypeError: Cannot read property 'next' of null at $getNext (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:5522:143) at $addCanonical (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:29958:152) at $remove_40 (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:29984:7) at Object.onDeactivated_2 [as onDeactivated_0] (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:30058:88) at Object.onRemovedFromParent_1 [as onRemovedFromParent_0] (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:10167:89) at $notifyRemovedFromParent (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:9330:75) at $removeChildrenInner (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:9743:5) at $removeChildren (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:9716:3) at $removeChild_2 (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:9703:168) at $removeChild_4 (http://waveinabox.net:9898/webclient/96B870181B409D6BBA993A96FD3E4D3D.cache.html:15277:5) arguments: next, type: non_object_property_load Unknown.$fillInStackTrace (StackTraceCreator.java:147) Unknown.fillInStackTrace (StackTraceCreator.java:387) Unknown.JavaScriptException_0 (Throwable.java:46) Unknown.caught_0 (Exceptions.java:29) Unknown.$getNext (LinkedPruningSequenceMap.java:52) Unknown.$addCanonical (InlineAnchorLiveRenderer.java:272) Unknown.$remove_40 (InlineAnchorLiveRenderer.java:262) Unknown.onDeactivated_2 (InlineAnchorLiveRenderer.java:313) Unknown.onRemovedFromParent_1 (AgentAdapter.java:253) Unknown.$notifyRemovedFromParent (ContentNode.java:508) Unknown.$removeChildrenInner (ContentElement.java:564) Unknown.$removeChildren (ContentElement.java:526) Unknown.$removeChild_2 (ContentElement.java:505) Unknown.$removeChild_4 (ContentRawDocument.java:198) Unknown.$removeChild_5 (ContentRawDocument.java:195) Unknown.removeChild_0 (RepaintingPersistentContent.java:72) Unknown.deleteElementStart_2 (IndexedDocumentImpl.java:879) Unknown.apply_105 (Nindo.java:367) Unknown.$apply_40 (Nindo.java:689) Unknown.$consumeAndReturnInvertible (IndexedDocumentImpl.java:399) Unknown.$consumeLocal (ContentDocument.java:1698) Unknown.$consumeAndReturnInvertible_0 (ContentDocument.java:239) Unknown.consume_8 (EditorOperationSequencer.java:49) Unknown.$deleteNode (Locator.java:39) Unknown.exec_0 (WaveletBasedConversationBlip.java:563) Unknown.$with (MutableDocumentImpl.java:696) Unknown.with_$_0 (MutableDocumentProxy.java:114) Unknown.$clearInlineReplyAnchors (WaveletBasedConversationBlip.java:547) Unknown.$deleteThread_0 (WaveletBasedConversationBlip.java:416) Unknown.$deleteBlip_0 (WaveletBasedConversationThread.java:250) Unknown.$delete_1 (WaveletBasedConversationBlip.java:331) Unknown.$delete (ActionsImpl.java:129) Unknown.onMouseDown_3 (MenuController.java:76) Unknown.$dispatch_16 (EventDispatcherPanel.java:271) Unknown.dispatch_21 (EventDispatcherPanel.java:270) Unknown.$dispatch_14 (EventDispatcherPanel.java:175) Unknown.onMouseDown (EventDispatcherPanel.java:276) Unknown.dispatch_6 (MouseDownEvent.java:53) Unknown.$doFire (SimpleEventBus.java:204) Unknown.$fireEvent_0 (SimpleEventBus.java:103) Unknown.$fireEvent (HandlerManager.java:101) Unknown.$fireEvent_1 (Widget.java:103) Unknown.fireNativeEvent (DomEvent.java:116) Unknown.$onBrowserEvent (Widget.java:151) Unknown.onBrowserEvent (Widget.java:137) Unknown.dispatchEvent_1 (DOM.java:1264) Unknown.anonymous (DOMImplStandard.java:187) Unknown.entry0 (Impl.java:214) Unknown.anonymous (Impl.java:57)

Michael, can you please take a look at this issue?

I found a way to reproduce this exception. It happens while trying to delete an inline blip while in edit mode.

Yes, I was planning on fixing this this week.

You are correct that the bad state occurs when the blip being edited gets deleted. Once that happens, any later attempt to restore focus to another blip will cause a shiny.

The problem is that EditSession needs to be notified if the blip being edited gets deleted, so it can terminate the edit session in a way that does not crash on deleted blips. The simple approach of simply listening to the conversation model for an onBlipDeleted event of the being-edited blip will work 99% of the time, but it won't work for a compound deletion when the blip being edited is transitively contained by another object that gets deleted (thread, blip, or conversation), because the conversation model only broadcasts events for top-most objects of deleted parts. To handle the compound case requires being able to examine the deleted object and traverse its contents, in order to see if the being-edited blip is in there, but structural information of deleted objects is not reliable due to how document XML deletion works.

An alternative approach is to have the view objects notify listeners if/when they get detached from the DOM. Again, the transitive case needs to be solved for that approach.

In short, I think there is a fairly small, direct fix that will solve this issue except for the very rare cases of compound deletions, which may not be solvable quickly or nicely. That may be good enough for a long time.

will do thanks.

Has there been a fix on this issue. I am trying to reproduce it and can't seem to get an exception.

Hmm, yep seems like it is gone. Maybe fix for issue 262 solved also this one?

This bug is still easily reproducible:

1. Create a wave.
2. Click Reply on the root blip.
3. Click Delete on the newly created blip.

I'm pretty sure this bug occurs when the you're editing a blip in a reply thread that has no other siblings, and that reply thread gets deleted. However, I think my explanation above was way off - it doesn't match the stack trace, so I don't think the issue is related to edit sessions - it appears something to do with updating the internal structures that track the anchor doodads that are used to place threads inline inside the document content of their parent blip.

Gah - sorry, I should have updated the corresponding JIRA issue.