854331 - Firefox doesn't scroll to active tab properly

Status: RESOLVED INVALID

(Firefox :: Tabbed Browser, defect)

Description

[Mark Straver]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:20.0) Gecko/20100101 Firefox/20.0
Build ID: 20130320062118

Steps to reproduce:

I prefer not to open related tabs next to the current tab, and as such have browser.tabs.insertRelatedAfterCurrent set to false. Previous versions of Firefox would, when opening a new tab from a link (ctrl+click, middle-click), properly go to the newly created tab (even if scrolling the tab bar was required with a larger number of tabs). 


Actual results:

Instead of scrolling to the active tab, the tab bar scrolls only one position, leaving the active tab off-screen.


Expected results:

The tab bar should have scrolled to the position of the new (now active) tab on the tab bar. with relatedaftercurrent to false, meaning it should scroll to the last tab position if off-screen.

Comment 1

[(mostly gone) XtC4UaLL [:xtc4uall]]

Can you provide a Regression Range using e.g. https://github.com/mozilla/mozregression/ ?

Comment 2

[Mark Straver]

Hmm... Looking at mozregression I found something out:
Apparently, for some unknown reason, the option to control "switch to the new tab immediately", pref browser.tabs.loadInBackground, which I (obviously) normally set to false had been reset during one of my upgrades - none of the other prefs got reset as far as I know, which makes this a conundrum. I have no idea when this might have happened, as I did a few large version jumps. Setting this as-intended makes the scrolling work as it should in the current Fx20 beta i'm using as well.