648709 - Menu closes while hovering on Menu items (en.lernu.net)

Status: RESOLVED WONTFIX

(Firefox :: General, defect)

Description

[Dominique Pelle]

User-Agent:       Mozilla/5.0 (X11; Linux i686; rv:2.0b13pre) Gecko/20110322 Firefox/4.0b13pre
Build Identifier: Mozilla/5.0 (X11; Linux i686; rv:2.0b13pre) Gecko/20110322 Firefox/4.0b13pre

If you go on http://en.lernu.net/
there is a menu with items:
- Main Page
- Introduction
- Courses
- Learning
- Communication
- etc.

If you hover the mouse over item "Communication", a menu pops up (good so far).  Move the mouse down to try to select the last menu item and notice that menu closes spontaneously before mouse can reach the last item.  It makes it impossible to select the last item in the menu.

I can reproduce it with FF-4.0 4.0b13pre (2011-03-22)  (Ubuntu-10.04.2)

The bug does not happen with Firefox-3.6.17 and does not happen with Chromium-10.0 either.  I only see it with Firefox-4.0.

Many other people can reproduce the bug on Windows too and on Linux, all with FF-4.0 according to this forum: http://en.lernu.net/komunikado/forumo/temo.php?t=8742  (in Esperanto).

It happens nearly all the time (99% of the time).


Reproducible: Sometimes

Steps to Reproduce:
1. go to http://en.lernu.net
2. hover mouse over menu "Communication"
3. move mouse down to try to select last menu item "Forum"
4. Observe that menu closes before mouse can reach last menu item

Actual Results:  
Observe that menu closes before mouse can reach last menu item


Expected Results:  
I would expect that menu does not close spontaneously.  Menus is not closed in other browsers I tried (FF-3.1.6.17 and Chromium-10.0).

Comment 1

[George Carstoiu]

Mozilla/5.0 (X11; Linux i686; rv:5.0a2) Gecko/20110417 Firefox/5.0a2

Works fine for me with the latest Aurora build.

Can you please try reproducing it on a clean profile:
http://support.mozilla.com/en-US/kb/Managing%20profiles

Comment 2

[Dominique Pelle]

George Carstoiu wrote:

> Mozilla/5.0 (X11; Linux i686; rv:5.0a2) Gecko/20110417 Firefox/5.0a2
> 
> Works fine for me with the latest Aurora build.

I just installed the nightly build of Firefox (about screeen says version 6.0a1) on Ubuntu-10.04.  And the bug is still there.  It does not always happen in the menu "Communication" at http://en.lernu.net but if I try other menus it sometimes still happens frequently. It seems to happen more frequently in long menus such as menu "Help Pages" or menu "About Lernu!" (at the top of the page http://en.lernu.net). Although it's not 100% reproducible, it is easy to reproduce: only try hovering the menus without clicking and move mouse donw to try to go on last menu item, bug generally then happens: menu disappears sponteneously before reaching the last item.  

Again, I do not see this bug with old Firefox-3.6 or Chromium.
 
> Can you please try reproducing it on a clean/new profile:
> http://support.mozilla.com/en-US/kb/Managing%20profiles

Done that, created a clean profile using command:

$ firefox-trunk -ProfileManager

And bug still happens with a clean profile.

Comment 3

[Dominique Pelle]

Just to precise that the full version of the browser with which I still see the bug:

Mozilla/5.0 (X11; Linux i686; rv:6.0a1) Gecko/20110413 Firefox/6.0a1

(obtained by typing "about:support" in URL)

Comment 4

[aravindm]

Confirmed on Mozilla/5.0 (Windows NT 6.1; rv:6.0a1) Gecko/20110419 Firefox/6.0a1

Menu closes before the mouse reaches the last menu item.

Comment 5

[George Carstoiu]

Mozilla/5.0 (X11; Linux i686; rv:6.0a1) Gecko/20110420 Firefox/6.0a1

I was finally able to reproduce the issue. Checked whether it is reproducible on onther browsers and it is not.

Setting resolution to NEW.

Thanks Dominique!

Comment 6

[aravindm]

Regression Range : 
works: 
Mozilla/5.0 (Windows NT 6.1; rv:2.0b9pre) Gecko/20110105 Firefox/4.0b9pre
broken:
Mozilla/5.0 (Windows NT 6.1; rv:2.0b9pre) Gecko/20110106 Firefox/4.0b9pre
pushlog:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=d2bd42931b03&tochange=c6e65b6259db

Comment 7

[u279076]

Does this happen with html5.parser.enable set to false?

Comment 8

[Dominique Pelle]

Anthony Hughes wrote:

> Does this happen with html5.parser.enable set to false?

Yes, it still happens with "html5.parser.enable" set to false.
html5.parser.enable was set to true by default, I set it to false
in URL "about:config" and bug still happens.

I used firefox-trunk on Ubuntu-10.04.2:

Mozilla/5.0 (X11; Linux i686; rv:6.0a1) Gecko/20110422 Firefox/6.0a1

Comment 9

[u279076]

Attachment: Testcase (IE7-off)

I've created a not-so-minimized testcase.  Line 8 of this testcase contains:

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />

By commenting out this line, the menu behaves as it should.

According to http://msdn.microsoft.com/en-us/library/cc288325%28v=vs.85%29.aspx this line of code should cause any browsers to emulate IE7 when visiting this page. In other words, it's a "hack" to enable web developers to not worry about web standards:

"If your site does not display correctly in Internet Explorer, you can either update the site to support the latest web standards (preferred) or you can force Internet Explorer to display your content as if it were being viewed in an older version of the browser."

So now I'm thinking this is either:
a) Site-specific (Tech Evangelism), or
b) a Firefox IE7 Emulation bug...

Comment 10

[u279076]

Attachment: Testcase (IE7-on)

Here is the version of the testcase with IE7-emulation turned back on.

Comment 11

[Dominique Pelle]

I still see this bug in Firefox-4.0.1 on Linux.

However, the nightly build now works fine.  Bug appears to have been fixed at least in this version:

Build identifier: Mozilla/5.0 (X11; Linux i686; rv:7.0a1) Gecko/20110609 Firefox/7.0a1

Comment 12

[u279076]

Resolving WONTFIX based on previous comment.