Re: [STUMP] Interesting Bug...

[Ben Spencer]

Hi,

On Tue, Jan 19, 2010 at 10:47:57PM -0500, Brit Butler wrote:
> I have a Lenovo X200 laptop with a dock, the dock is connected to an
> external flatscreen via VGA. With Xmonad I would get home, drop on the dock,
> use lxrandr to enable the second screen and be off to the races. This didn't
> work with stumpwm so I wrote the fix-layout defcommand in my .stumpwmrc
> which works handily.

What exactly does it not do that you expect it to?


> Connected to stump with slime, it's interesting to note
> that (current-screen) always returns the screen stumpwm first loaded with,
> even if I turn OFF the VGA monitor in lxrandr and turn on the laptop screen
> (or vice versa). (current-head) always shows the accurate resolution of the
> active screen. It's also interesting to note that *screen-list* never has
> more than one entry, including with both screens on in lxrandr.

Terminology note: 'screen' refers to X screens, 'head' refers to
Xinerama heads.  It sounds like you have two heads within one screen,
so I'd expect *screen-list* to only show one entry.  However, when you
have both heads enabled, (screen-heads (current-screen)) should have
two entries.  The command:

xdpyinfo -ext XINERAMA | grep head

should show dimensions that match these entries.


> So, the weird bug:
> When I "flip" monitors in lxrandr and hit OK, stumpwm hangs. The window I'm
> in receives all keyboard input and, generally, it's like stumpwm isn't there
> at all. If I switch to a tty, open emacs, slime-connect to stump and try to
> run (loadrc) or most anything in the :stumpwm package, I get a backtrace
> like that seen in http://redlinernotes.com/docs/stumpwm_backtrace.txt. The
> brief absence of the former (current-head) causes something not to
> type-check as head and even though a new head takes its place, stump hangs.
> Aborting to SLIME's toplevel in the debugger returns stump to it's normal
> state. I'm happy to try and produce fuller debugging information.

Are you running the latest from git?  This sounds rather like a bug
that was fixed relatively recently and isn't in the latest release.  I
get a 404 from that backtrace link btw.


> It would be nice in any case if anyone could tell me how to add a
> *head-changed-hook*, so that I can have fix-layout run automatically when I
> switch heads.

xrandr changes are handled in the :configure-notify event handler in 
events.lisp.


Hope some of this is helpful :)

Ben