1471935 - DevTools 3-pane not rendered on spam-clicks

Status: NEW

(DevTools :: Inspector, defect, P3)

Description

[Cristian Fogel, QA [:cfogel]]

Attachment: 3pain_3rulesOnPageRefresh.gif

[Affected versions]:
- Firefox: 61.0, 62.0b3, 63.0a1 (2018-06-27)

[Affected platforms]:
- Win 10x64, Ubuntu 16.04LTS, macOS 10.13.4

[Steps to reproduce]:
1. Launch Firefox;
2. Open the devtools-inspector (CTRL+SHIFT+C / Tools -> Web Developer -> Inspector);
3. Refresh the page;
4. Spam-Click on the Toggle the 3-pane inspector button.

[Expected result]:
- the devTools pannels are rendered and displayed properly

[Actual results]:
- the rules tab is multiplied and extras are displayed as empty;
- the whole 3-pane section is empty;

[Regression range]:
- doesn't seem to be a regression;
- a mozzreegression run gave the following result:
https://bugzilla.mozilla.org/show_bug.cgi?id=1369945


[Additional notes]:
- attached screencast with the issue;
- step 3 can be skipped in some casses, or for step 4 to work a web-page with rich content needs to be accessed; 
- closing and reopening the devTools "resets" the issue;