User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b1pre) Gecko/20080925033548 Minefield/3.1b1pre Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b1pre) Gecko/20080925033548 Minefield/3.1b1pre When browser.tabs.closeWindowWithLastTab is set to False and the last tab is closed, another tab briefly appears then disappears. This shouldn't happen Reproducible: Always Steps to Reproduce: 1. Set browser.tabs.closeWindowWithLastTab to False 2. Open a webpage in one tab 3. Middle click the tab to close it Actual Results: Another tab briefly appears then disappears. This shouldn't happen. Expected Results: The tab should close the page and revert to a blank tab without creating a second tab and having that disappear.

I can confirm this using Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b1pre) Gecko/20080925033548 Minefield/3.1b1pre

Is this going to be committed to Firefox?

Bug is still there on the latest trunk/branch nightlies: 1) Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090130 Minefield/3.2a1pre 2) Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b3pre) Gecko/20090130 Shiretoko/3.1b3pre Is it going to be fixed in upcoming Firefox 3.1 release?

now without hacking addTab

With this patch, if you close the last tab I can see the close-button on the empty tab for a split second. Seeing this on vista. Would be nice if the X wouldn't appear.

(In reply to comment #7) > With this patch, if you close the last tab I can see the close-button on the > empty tab for a split second. Seeing this on vista. Would be nice if the X > wouldn't appear. Please file a new bug.

Filed bug #486280.

Tab B (Grey) is actually collapsed. The image is only for reference. I filed Bug 486129. The problem is a time lag (3). Now, the patch v2 causes serious regression. This patch break many third party themes. And, this patch greatly limits the tab design of the third party theme. https://bug486129.bugzilla.mozilla.org/attachment.cgi?id=370202 Piro told me that the more large patch is necessary to fix Bug 486129 and Bug 486280.

Comment on attachment 369064 [details] [diff] [review] patch v2 I think we need to wait for the followup patch from bug 486280 before we can land this. Please feel free to renominate then.

This is not fixed in Firefox 3.5b4

That's because it hasn't been checked into that branch at this time (you can see that the patch attached to this bug is still pending approval). You can verify that it's fixed with a recent mozilla-central nightly (version 3.6a1pre).

Comment on attachment 369064 [details] [diff] [review] patch v2 a191=beltzner, please land with bug 486280

This checkin was in a range identified with a Ts Shutdown regression on Windows: Regression: Ts Shutdown increase 27.64% on WINNT 5.1 Firefox3.5 Previous results: 357.263 from build 20090506145316 of revision 486b76052a94 at 2009-05-06 14:53:00 New results: 456.0 from build 20090506155401 of revision 7aa4483585bd at 2009-05-06 15:54:00 http://graphs-new.mozilla.org/graph.html#tests=[{"machine":32,"test":36,"branch":3},{"machine":33,"test":36,"branch":3},{"machine":34,"test":36,"branch":3},{"machine":35,"test":36,"branch":3},{"machine":48,"test":36,"branch":3}]&sel=1241564040,1241736840

verified FIXED on builds: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2a1pre) Gecko/20090527 Minefield/3.6a1pre ID:20090527031500 and Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1pre) Gecko/20090527 Shiretoko/3.5pre ID:20090527031214

In Firefox3.5b99 an X is still briefly visible when closing the last tab. Additionally if you undo the last closed tab a second tab briefly appears. Unsure if I should open a new bug for this or not.

(In reply to comment #18) That's bug 490166.

Er, the "X is still briefly visible when closing the last tab" is bug 490166. The "Undo Close Tab with a last blank tab briefly shows 2 tabs" part is bug 458011.

This bug's priority relative to the set of other polish bugs is: P1 - Polish issue that appears in the main window, or is something that the user may encounter several times a day. nice diagram :)