Bug 162123 – Uncaught Exception: null is not an object (evaluating 'this.listItemElement.classList')

• Status: RESOLVED
• Resolution: FIXED
• Component: Web Inspector

[Joseph Pecoraro]

Summary:
Uncaught Exception: null is not an object (evaluating 'this.listItemElement.classList')

Steps to Reproduce:
1. Inspect Element on an element deep in Shadow DOM
  => exception, element not selected in DOM Tree

Notes:
- The updateTitle is happening onexpand before the element is attached. The <li> is not created until attached.
- This alludes to some performance opportunities. Do we need to update title on expand if not yet attached?

-------
Uncaught Exceptions:
 - null is not an object (evaluating 'this.listItemElement.classList') (at DOMTreeElement.js:1257:45)
    _nodeTitleInfo @ DOMTreeElement.js:1257:45
    updateTitle @ DOMTreeElement.js:1133:55
    onexpand @ DOMTreeElement.js:506:25
    expand @ TreeElement.js:391:26
    reveal @ TreeElement.js:437:39
    revealAndSelect @ TreeElement.js:515:20
    _revealAndSelectNode @ DOMTreeOutline.js:291:36
    selectDOMNode @ DOMTreeOutline.js:132:34
    selectAndRevealDOMNode @ DOMTreeContentView.js:141:43
    showRepresentedObject @ ElementsTabContentView.js:82:50
    showRepresentedObject @ Main.js:1120:41
    showMainFrameDOMTree @ Main.js:1128:31
    _domNodeWasInspected @ Main.js:1784:30
    dispatch @ Object.js:170:30
    dispatchEventToListeners @ Object.js:177:17
    inspectElement @ DOMTreeManager.js:313:38
    nodeAvailable @ DOMTreeManager.js:331:32
    nodeAvailable @ [native code]
    ? @ DOMTreeManager.js:108:21
    _dispatchResponseToCallback @ InspectorBackend.js:311:27
    _dispatchResponse @ InspectorBackend.js:281:45
    dispatch @ InspectorBackend.js:157:35
    dispatchNextQueuedMessageFromBackend @ MessageDispatcher.js:42:34

[Radar WebKit Bug Importer]

<rdar://problem/28352900>

[Joseph Pecoraro]

Created attachment 289183 [details]
[PATCH] Proposed Fix

[WebKit Commit Bot]

Comment on attachment 289183 [details]
[PATCH] Proposed Fix

Clearing flags on attachment: 289183

Committed r206081: <http://trac.webkit.org/changeset/206081>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.