Bug 190966 – Web Inspector: Uncaught Exception: undefined is not an object (evaluating 'this._classListContainer.children')

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

[Devin Rousso]

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Inspected URL:        file:///Volumes/DATA/Build/Release/WebInspectorUI.framework/Resources/Main.html
Loading completed:    true
Frontend User Agent:  Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/605.1.15 (KHTML, like Gecko)
Dispatch Source:      Protocol Event

Protocol Event:
{"method":"DOM.attributeModified","params":{"nodeId":161,"name":"class","value":"mac-platform mojave latest-mac web show-invalid-characters show-whitespace-characters docked bottom meta-key-pressed"}}

Uncaught Exceptions:
 - undefined is not an object (evaluating 'this._classListContainer.children') (at GeneralStyleDetailsSidebarPanel.js:357:40)
    _populateClassToggles @ GeneralStyleDetailsSidebarPanel.js:357:40
    _handleNodeAttributeModified @ GeneralStyleDetailsSidebarPanel.js:301:39
    dispatch @ Object.js:170:30
    dispatchEventToListeners @ Object.js:177:17
    _attributeModified @ DOMManager.js:175:38
    attributeModified @ DOMObserver.js:47:41
    dispatchEvent @ InspectorBackend.js:298:42
    _dispatchEvent @ Connection.js:193:32
    dispatch @ Connection.js:71:32
    dispatch @ InspectorBackend.js:152:49
    dispatchNextQueuedMessageFromBackend @ MessageDispatcher.js:42:34

Additional Details:
    cause --> An uncaught exception was thrown while handling event: DOM.attributeModified
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I was unable to reliably reproduce this.  I just opened inspector2 and was shown this error.

[Devin Rousso]

Created attachment 353190 [details]
Patch

[Joseph Pecoraro]

Comment on attachment 353190 [details]
Patch

r=me

[WebKit Commit Bot]

Comment on attachment 353190 [details]
Patch

Clearing flags on attachment: 353190

Committed r237481: <https://trac.webkit.org/changeset/237481>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/45597933>