814300 - Loss of Scrollbars When overflow:hidden and display:none are Added Then Removed

Status: RESOLVED WORKSFORME

(Firefox :: Untriaged, defect)

Description

[Matt]

Attachment: testcase.zip

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/17.0 Firefox/17.0
Build ID: 20121119183901

Steps to reproduce:

This appears to be a new problem with the FF 17 stable release. I am including a couple of files for testing.

I have overflow-y:scroll on an element, in this case an iframe. First I applied overflow:hidden and display:none to the element. Next, I remove the display:none property and the element reappears with no scrollbars. If overflow:hidden is then removed, the vertical scrollbar does not come back.

However. If I remove overflow:hidden first, THEN remove display:none, I get the scrollbar back. This did not happen with the last three versions of FF.

The problem is that the JQuery library, possibly among other things, adds and removes this particular css in this particular order if you call certain animations, such as when someone uses .toggle().

I noticed that there were similar bugs reported (and then resolved) quite a long time ago, so I apologize if I should have added this to one of them. I figure this is a new instance, so a new report was in order.

Comment 1

[Paul Silaghi, QA [:pauly]]

I don't see (or may not understand) the issue loading the testcase.
Can you please provide some specific steps to reproduce? Or even a screenshot showing the problem?

Comment 2

[Matt]

It is best to use an addon such as Firebug to add/remove css to the iframe in realtime. If you load the test case in FF 17, and then use Firebug to add the css (and then remove it) in the order mentioned above, you will see what I mean. Alternatively, one could use the .toggle() method with jQuery. If you still don't see what the issue is, I'll re-do the testcase in a few days with the jQuery library included and a clickable button to show the result.

Comment 3

[Stephen Donner [:stephend] Not actively reading bugmail]

Martijn, any chance you could help take a look at this?

Comment 4

[Martijn Wargers (dead)]

Attachment: testcase

I can't reproduce this on Firefox19b, on MacOSX10.7.5. Can somebody check if the issue can be seen with the stable release?
If it can't be reproduced with this testcase, Matt, can you give an example of a site/page where you can see this bug?

Sorry for the delay.

Comment 5

[Paul Silaghi, QA [:pauly]]

Everything looks ok on FF 22, Mac OS X 10.7.5 using the testcase.
(In reply to Matt from comment #2)
> If
> you still don't see what the issue is, I'll re-do the testcase in a few days
> with the jQuery library included and a clickable button to show the result.
If you're still able to see this on FF 22 release, please make the above testcase and reopen this bug. Thanks.