408929 - Flickering when creating new tab or closing last (and only) one

Status: RESOLVED DUPLICATE of bug 543306

(Firefox :: Tabbed Browser, defect)

Description

[Marat Tanalin]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9b3pre) Gecko/2007121805 Minefield/3.0b3pre
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9b3pre) Gecko/2007121805 Minefield/3.0b3pre

In Fx 3, unlike Fx 2, there is flickering when:
1. creating new tab or
2. closing tab when this tab is only tab open at the moment while the option Tools -> Options -> Tabs -> "Always show the tab bar" is turned on.

That flickering effect is quite annoying and undesirable and even *dangerous* for epileptics in particular while evidently easy-to-fix.

Evident reason of this bug is that *window background* is shown *between* closed tab disappearing and next-to-focus tab (i.e. new tab on creating new tab, or "new" tab automatically created on closing tab which is already one and only open tab) is really shown. Solution is to prevent it by making transition *direct* from one tab to other tab without intermediate (short but noticeable) window background displaying.

Reproducible: Always

Steps to Reproduce:
1. create new tab;
2. create one more tab;
3. see to background of window at each iteration.
OR
1. turn on the option Tools -> Options -> Tabs -> "Always show the tab bar";
2. close all tabs except last one;
3. try to close last tab once and again;
4. see to background of window at each iteration.
Actual Results:  
Window background is displayed for a short while with noticeable flickering effect on creating every new tab or on trying to close last open tab.

Expected Results:  
Transition between two states (from one tab to another tab) should be direct, without intermediate window background displaying, as it is in Firefox 2 that have not this bug.

Firefox 3 is the first version of Firefox that have this bug.

Comment 1

[Marat Tanalin]

Ok, I've just checked Firefox 2 and discovered that this bug applies to it too to some extent. So, Firefox 3 is the first version of Firefox where this bug is *too noticeable* and enough to talk about it. Thanks.

Comment 2

[Marcia Knous [:marcia]]

To me the flickering is most noticeable when I am opening a new tab using  Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9b2) Gecko/2007121120 Firefox/3.0b2.

Comment 3

[Wayne Mery (:wsmwk)]

still see this?

Comment 4

[Marat Tanalin]

(In reply to comment #3)
> still see this?

3.6 (Gecko/20100115 Firefox/3.6)—yes.
3.7 (Gecko/20100211 Minefield/3.7a2pre)—no.

It seems the bug is fixed in current 3.7 nightlies.

Comment 5

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Marat, would you have time to check which nightly build on 1.9.3 fixed that problem?

Comment 6

[Marat Tanalin]

(In reply to comment #5)
> Marat, would you have time to check which nightly build on 1.9.3 fixed that
> problem?

2010-02-01-04-mozilla-central (Minefield/3.7a1pre)—bug exists.
2010-02-02-05-mozilla-central (Minefield/3.7a1pre)—bug is fixed.

Comment 7

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Thanks for re-checking. But I cannot see any candidate which could have fixed this bug. So we should leave it as WFM.

Comment 8

[Marat Tanalin]

Maybe depends on bug 543306 fixed on 2010-02-01.

Comment 9

[Henrik Skupin [:whimboo][⌚️UTC+1]]

That's it! Thanks. That check-in wasn't in the pushlog list for my query. Duping to bug 543306.

Comment 10

[Marat Tanalin]

By the way, this bug is reported far earlier than bug 543306, so I'm unsure the duping direction is right. ;-)

Comment 11

[Marat Tanalin]

Oh, I have accidentally resetted status (planned to just add comment). Reverting now.

Comment 12

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Time is relative. The patch on bug 543306 has already been fixed the issue. So the direction is correct.