[Xquartz-dev] some more "white rectangle" behaviour data

[Cameron Simpson]

On 04Dec2008 18:36, George Peter Staplin <georgeps at xmission.com> wrote:
> Quoted Cameron Simpson <cs at zip.com.au>:
>> [...] My GF is running 2.3.1 in rootless mode using icewm.
>> If she leaves her machine she uses fast user switching to go to the login
>> window. On return there are large while rectangles positioned where some
>> former apps used to be. They behave like the X11 root window; her X11 root
>> window context menus function in these areas.
>>
>> Restarting the window manager gets rid of most of these white rectangles;
>> the ones that remain appear (loosely) to be associated with things like
>> the mozilla/seamonkey URL bar and the URL completion drop down etc.
>
> Those sound to me like windows with the override_redirect attribute set 
> to True.  In which case the problem is probably not with quartz-wm, but 
> rather with the X11 server, or Xplugin that the X11 server uses.

As mentioned, quartz-wm is not running.

The large windows are related to conventional app windows. If you're
talking about those that remain after WM restart, yes, seems consistent.

>> I am speculating that these are the window frames used by the WM for
>> reparenting (in the case of apps) and merely "withdrawn" windows in the
>> case of the ones that look like the location bar drop down.
>
> A traditional WM should just ignore the override_redirect windows, and  
> not reparent them.  In fact reparenting some override_redirect windows  
> results in apps failing.  I learned this during an experimental  
> project...

It rings a bell with me too.

I'm also wondering if these windows are the apple-land windows that I
imagine must get made to render the rootless X11 top level windows.
The override redirect is then a slight red herring. Suppose that these
rectangles are the apple-land windows for top level rootless windows,
devoid of the interior X11 app scribbling. It looks like the X11 server
loses track of some of them when an X11 app closes the window, or if the
app exits and the server has to clean up.

[...]
> This is helpful information.  I think this will help us track it down.  
> Thus far I've not been able to duplicate the problem, and it sounds like 
> Jeremy hasn't either from what I recall.

I have scenarios of my own, too.

My own 2.3.2rc1 setup is configured for full screen mode. I seem to get
window associated with apps that are made before the WM starts. So if I
start an X11 app and the X server is started as a side-effect then there
tends to be a big white rectangle in apple land where the app starts.
Click on it and the full screen X11 desktop appears. Interestingly, the
white rectangle is visible inside X11 too.

A short experiment now, as I type this, shows that the "Click on it
and the full screen X11 desktop appears" is an effect of apple land app
focus change - it only happens if the focused apple app is not the X11
server. If X11 has the focus (enter X11, option-command-A out of full
screen mode) then clicking on the big white apple land rectangle is just
a bit of X11 root window - my FVWM root context menu shows up and I do
not re-enter full screen X11 mode.

A restart of my WM also removes the apple land large white rectangle.
The inside-X11 white rectangle is still there. It is above the root window
(shown by an "xsetroot -solid blue" leaving it untouched) and below the
X11 apps (shown by moving them around). It does behave as root window
context, so I presume mouse clicks are caught by it or fall through.

[Flips back and forth a little..] Argh. The big white rectangle is
visible in apple land again - same size and place.

I can perform other experiments if you can suggest something specific to
test.
-- 
Cameron Simpson <cs at zip.com.au> DoD#743
http://www.cskk.ezoshosting.com/cs/

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