833146 - Tabs clicked by mouse do not render until mouse interaction with url bar

Status: RESOLVED INCOMPLETE

(Firefox :: Tabbed Browser, defect)

Description

[Chris]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/20100101 Firefox/18.0
Build ID: 20130116073211

Steps to reproduce:

I believe this behavior is what many users are describing as "slow" or unresponsive tabs in Firefox 18. The issue is not with "speed" per se - in fact, the issue appears to be that the newly selected tab is not re-rendered in the window UNTIL the mouse cursor interacts with (hovers over) the URL bar.

Open two tabs in Firefox 18.0.1. Click on the tabs to switch between the two.


Actual results:

Nothing. The URL bar updates the address, but the web page is not redrawn. This is an intermittent issue, but will happen multiple times while switching between tabs with the mouse. If the mouse cursor is hovered over the URL bar, the newly selected tab is instantly drawn in the content area.


Expected results:

The webpage should be redrawn to the newly selected tab's location.

Firefox 18.0.1, Windows 7 64 bit

Comment 1

[Chris]

I believe this bug should be merged with the other various "slow" or unresponsive tabs bugs, as this is the true nature of the bug - tabs not re-rendering in the content area when they are clicked on by a mouse.

Comment 2

[Chris]

Edit: the URL bar does NOT update to the address of the newly selected tab. Nothing changes in the UI until the mouse hovers over the URL bar.

Comment 3

[Chris]

This also may require a heavy JavaScript page, such as Gmail.

Comment 4

[Ioana (away)]

Can you reproduce this issue in safe mode? What about with a clean profile?
http://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
http://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

WFM on Firefox 18.0.1 and the latest Nightly.

Comment 5

[Chris]

I disabled all add-ons, and the issue persists, but I'm not doing any more debugging for this issue. Firefox should work with a non-clean profile. 
If you only support Firefox with no history, no bookmarks and no cookies, what's the point?

There are multiple bugs here re: tabbed browsing being slow or non-responsive. I think I have isolated the behavior fairly well, and because the same issue is posted under several bugs since FF 18.0.1, it is obviously a real bug.

But, you're perfectly welcome to not address the issue because apparently FF is only supposed to work with a 100% clean profile under a brand new install. No wonder FF is now the third most popular browser behind both IE and Chrome.

Comment 6

[Ioana (away)]

Chris, I asked you to try with a clean profile as part of the troubleshooting process, not in the idea that we only support that.

If your issue doesn't reproduce on a clean profile, it could be the fault of an add-on or theme you installed, a pref you changed, interactions 3rd party software could have had with the browser files etc. We need troubleshooting to know where to look for the bug to get it fixed.