Bug 160604 – REGRESSION (r201245): switching between Computed and Visual Styles panels causes internal error

• Component: Web Inspector
• Status: RESOLVED FIXED

[Matt Baker]

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.

[Radar WebKit Bug Importer]

<rdar://problem/27723416>

[Matt Baker]

Regressed in https://trac.webkit.org/changeset/201245.

[Radar WebKit Bug Importer]

<rdar://problem/27724305>

[Matt Baker]

Created attachment 285530 [details]
[Patch] Proposed Fix

[WebKit Commit Bot]

Comment on attachment 285530 [details]
[Patch] Proposed Fix

Clearing flags on attachment: 285530

Committed r204244: <http://trac.webkit.org/changeset/204244>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.