551678 - Buggy mouse tracking with fvwm manual/active placement (reproducible with -safe-mode)

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Vincent Lefevre]

User-Agent:       Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100308 Iceweasel/3.5.8 (like Firefox/3.5.8)
Build Identifier: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100308 Iceweasel/3.5.8 (like Firefox/3.5.8)

When using manual window placement (fvwm's ManualPlacement, a.k.a. active placement), Firefox doesn't track the mouse correctly. For instance, it may think that the mouse pointer is still over the tab bar while it is no longer over it, yielding buggy behavior. See steps to reproduce below: this is always reproducible in safe mode.

Reproducible: Always

Steps to Reproduce:
1. Choose the fvwm window manager with ManualPlacement (steps 6 and 7 below are part of manual placement): Style "*" ManualPlacement (in fact, I've tried with ActivePlacement, but ManualPlacement should be better to reproduce the bug on some configurations).
2. Run: firefox -safe-mode
3. Open a web page that has links (optional, depending on whether the current web page is OK or not).
4. In the menu bar, click on "Tools". Make sure that the "Error Console" item appears partly over the tab bar, otherwise the bug may not be reproducible.
5. Click on "Error Console" (the mouse pointer must be at the tab bar level).
6. Move the mouse pointer to position the error console over the document area (web page). What's important IMHO is that when the error console appears, the mouse pointer isn't over the tab bar.
7. Click with the left button to make the error console appear.
8. Move the mouse pointer over the links of the web page.
Actual Results:  
When the mouse pointer is over a link, the correct behavior (arrow replaced by a hand, URL appears in the status bar) occurs for a fraction of second (hardly visible), then the mouse pointer is changed back to an arrow and the URL is replaced by "Done" in the status bar, as if the mouse pointer were moved to an empty area (or to the tab bar).
Actually, when testing this with the Tab Mix Plus extension, a close button may appear over some tab, suggesting that Firefox thinks that the mouse pointer is still over the tab bar (at the position where the click over the menu item was done?).
This buggy behavior stops once one moves the mouse pointer to the tab bar, then back to links on the web page.

Expected Results:  
When the mouse pointer is over a link, the arrow should be replaced by a hand and the URL should appear in the status bar.

FYI, here's how ManualPlacement is described in the fvwm man page: The user is required to place every new window manually. The window only shows as a rubber band until a place is selected manually. The window is placed when a mouse button or any key except Escape is pressed. [...]

Comment 1

[Vincent Lefevre]

I can reproduce exactly the same effects (as described by Actual Results) with Firefox 3.6 under Mac OS X, but I don't know what conditions trigger them.

Comment 2

[Tyler Downer [He/Him]]

Reporter, are you still seeing this issue with Firefox 3.6.13 or later in safe mode or a fresh profile? If not, please close. These links can help you in your testing.
http://support.mozilla.com/kb/Safe+Mode
http://support.mozilla.com/kb/Managing+profiles
Also, ensure you update all your plugins (Flash, Reader, java, quicktime, etc) to the latest version available on the vendor's website.

Comment 3

[Vincent Lefevre]

I can no longer reproduce this problem.

Comment 4

[Vincent Lefevre]

Actually I can reproduce a part of the problem with:

  Mozilla/5.0 (X11; Linux x86_64; rv:5.0) Gecko/20100101 Firefox/5.0 Iceweasel/5.0

The problem with the links is no longer there, but there's still at least a minor problem: when I click on the menu item (Error Console), the tab under the mouse pointer is highlighted and remains highlighted after the error console appears and until the mouse pointer is moved over the main window.

Note: to be able to reproduce it in safe mode here, I need to make the bookmarks toolbar visible and deselect "tabs on top". In this case, the "Error Console" menu item is over the tab bar. In practice, the layout depends on the installed extensions and possibly the GUI configuration (e.g. font size).

Comment 5

[Phoenix]

Is second part of the problem reproducible in current Firefox versions?

Comment 6

[Vincent Lefevre]

It seems that the "Error Console" menu item can no longer be over the tab bar with Iceweasel. However I could try the same thing with the "Downloads" menu item. The tab under the mouse pointer is highlighted until I position the Downloads window (but not after, so that the problem mentioned in Comment #4 no longer occurs). What happens before the window is placed is a very minor problem (probably coming from the fact that the window manager is blocking events until the window is placed, so that there is no chance of redraw). And things have changed again in Nightly, where I can't even trigger this minor problem.