Summary: Switching between Computed and Visual Styles panels causes internal error. Steps to Reproduce: 1. Open Inspector > Elements 2. Show Styles sidebar if necessary 3. Switch from Computed panel to Visual panel => [Error] TypeError: undefined is not an object (evaluating 'this._selectorSection.update') refresh — VisualStyleDetailsPanel.js:64 _refreshPreservingScrollPosition — StyleDetailsPanel.js:143 nodeStylesRefreshed — StyleDetailsPanel.js:114 dispatch — Object.js:162 dispatchEventToListeners — Object.js:169 fetchedComputedStyle — DOMNodeStyles.js:228 ... 4. When switching from Visual to Computed => [Error] TypeError: undefined is not an object (evaluating 'this._propertiesTextEditor.style = this.nodeStyles.computedStyle') refresh — ComputedStyleDetailsPanel.js:130 _refreshPreservingScrollPosition — StyleDetailsPanel.js:143 nodeStylesRefreshed — StyleDetailsPanel.js:114 dispatch — Object.js:162 dispatchEventToListeners — Object.js:169 fetchedComputedStyle — DOMNodeStyles.js:228 ... Note: I expected this to be a regression caused by https://trac.webkit.org/changeset/203253, but it looks like it was broken earlier.
<rdar://problem/27723416>
Regressed in https://trac.webkit.org/changeset/201245.
<rdar://problem/27724305>
Created attachment 285530 [details] [Patch] Proposed Fix
Comment on attachment 285530 [details] [Patch] Proposed Fix Clearing flags on attachment: 285530 Committed r204244: <http://trac.webkit.org/changeset/204244>
All reviewed patches have been landed. Closing bug.