783647 - Tab scrolling problems with more than 64 tabs

Status: UNCONFIRMED

(Firefox :: Tabbed Browser, defect)

Description

[Doug Bell]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:14.0) Gecko/20100101 Firefox/14.0.1
Build ID: 20120713134347

Steps to reproduce:

Open a lot of tabs over a period of time.  Windows 64-bit Firefox v.14.0.1.


Actual results:

Everything worked normal until the 64th or 65th tab was opened (not sure which) in a window.  At that point the new tab, which was the currently displayed tab, did not appear in the tab bar and I was not able to scroll the tabs to the right.  Adding yet another tab allowed me to scroll to see the previously-added-and-not-visible-in-the-tab-bar tab in the tab bar, but not the last tab added.  Also, scrolling the tab bar in either direction was very sluggish and unresponsive.  With enough scrolling back-and-forth the behavior could change to allow scrolling to the last tab, but the sluggish behavior continued.


Expected results:

When the new tab was opened and switched to, the tab should have been visible in the tab bar.  Also, it should have been possible to scroll to the new tab.  The performance of tab bar scrolling should not have latencies measured in seconds.