Bug 162123 - Uncaught Exception: null is not an object (evaluating 'this.listItemElement.classList')
Summary: Uncaught Exception: null is not an object (evaluating 'this.listItemElement.c...
Alias: None
Product: WebKit
Classification: Unclassified
Component: Web Inspector (show other bugs)
Version: WebKit Nightly Build
Hardware: All All
: P2 Normal
Assignee: Joseph Pecoraro
Keywords: InRadar
Depends on:
Reported: 2016-09-17 17:17 PDT by Joseph Pecoraro
Modified: 2016-09-18 10:38 PDT (History)
7 users (show)

See Also:

[PATCH] Proposed Fix (3.76 KB, patch)
2016-09-17 17:28 PDT, Joseph Pecoraro
no flags Details | Formatted Diff | Diff

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Description Joseph Pecoraro 2016-09-17 17:17:26 PDT
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

- 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
Comment 1 Radar WebKit Bug Importer 2016-09-17 17:17:40 PDT
Comment 2 Joseph Pecoraro 2016-09-17 17:28:43 PDT
Created attachment 289183 [details]
[PATCH] Proposed Fix
Comment 3 WebKit Commit Bot 2016-09-18 10:38:42 PDT
Comment on attachment 289183 [details]
[PATCH] Proposed Fix

Clearing flags on attachment: 289183

Committed r206081: <http://trac.webkit.org/changeset/206081>
Comment 4 WebKit Commit Bot 2016-09-18 10:38:45 PDT
All reviewed patches have been landed.  Closing bug.