714382 - Leftmost tab is hidden when reopening browser window

Status: RESOLVED WONTFIX

(Firefox :: Extension Compatibility, defect)

Description

[Alex]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0) Gecko/20100101 Firefox/10.0
Build ID: 20111228055358

Steps to reproduce:

Reopened Firefox 10, restoring the previous session automatically.


Actual results:

In two of the three windows that reopened, the left-most tab on each was invisible. All other tabs were present. Viewing each window in 'Tab Group View' correctly displays the left-most tab, though it is not shown at all in normal view. Dragging the visible tabs around causes the '+' (New Tab) button, which should always be on the left (?) to change position, so that it is sometimes in-between tab headers.


Expected results:

The left-most tab should be displayed when restoring a session/reopening a window. Re-ordering tabs by dragging their headers should not cause the '+' button (fake tab header) to move out of order.

Comment 1

[Dão Gottwald [:dao]]

Can you reproduce this with add-ons disabled?

Comment 2

[Alex]

Yeah, same issue is present then.

Comment 3

[Ioana (away)]

Verified as WFM on:
Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:12.0a1) Gecko/20120109 Firefox/12.0a1

All the tabs were visible in all the windows. Tabs could be dragged without any issues too.

Comment 4

[Andrew Buehler]

I am experiencing this same behavior, in Iceweasel 10.0.9. Five of my six windows exhibit the problem.

I have tried to work around the issue by dragging individual tabs to a new window, which is described elsewhere as a per-session workaround, but the same problem occurred in that window: the tab bar showed only the "New Tab" button.

This appears to be the same problem reported in bug 774943, which was closed due to the reporter not testing in a clean profile (on the grounds that A: since session restore is never in a clean profile, the problem will never occur in that case, and B: it's a serious problem regardless of whether the profile is clean or not).

In that bug, one user reported that the problem was being caused by the add-on "Google Search By Image" v0.3.

In my case, selectively disabling add-ons indicates that this seems to be being caused by either of two add-ons (independently): "Tab To Window 1.2.9" and my own locally-updated-for-post-3.x version of Firesomething. Disabling both of those makes the problem go away; enabling either of them brings it back. (Note that the same version of Firesomething seems to work fine in a separate install of Firefox 15.)

The question would seem to be, what is the underlying mistake here? It could be something the add-ons are doing which is now wrong, or it could be something in the underlying browser which the add-ons are exposing. If it's the former I'd like to know what it is (if only so that I can fix Firesomething), and if it's the latter it needs to be fixed in Firefox - although, as it doesn't seem to be security-related, perhaps not in the ESR.

Comment 5

[Jorge Villalobos [:jorgev] (he/him)]

Mass-closing old Extension Compatibility bugs that relate to legacy add-ons or NPAPI plug-ins. If you think this bug is still valid, please reopen or comment.

Sorry for the bug spam, and happy Friday!