2009/8/10 Tim Connors <tconnors@astr...>:
> G'day,
>
> I have one specific application (skycat -
> http://archive.eso.org/cms/tools-documentation/skycat
> )

Which I downloaded, had to install TCL8.4 and friends, then it bombed
out with a BLT error, and I'm giving up bothering to try to get this
fixed -- so I can't be arsed.  Way to go.  Tcl/Tk failure *yet again*.

> that when iconified, just disappears from the window list, the taskbar,
> etc (this is even with the default config file)

Right -- so this will be some obscure thing then.  Is this thing
somehow becoming unmanaged?  Can you get xprop or FvwmIdent or
something on this window?

> The application (a tcl/tk app) is still running, and I can get the window
> back by restarting fvwm (as soon as the first fvwm process exec()s itself
> to death, the window pops back up underneath everything else in Z order).

This is meaningless -- so it's not being raised?  Fair enough, FVWM
honours the stacking order across restarts.

> This doesn't happen in mwm or gnome etc, although twm actually kills the
> application outright.

I'd consider twm's action a good thing here.

> No other tcl/tk apps on the system behave in this way.  With FvwmIdent, I
> noticed that on all but one of the installations of skycat we have here,
> the "Icon Name" property was blank (the other said "SkyCat/IMG", but I
> happen to know this was set after the program was initialised, and it
> would have started off as blank; it still disappears by default when
> iconified).  All of the other properties were sane.

Right -- well this is legal by the ICCCM, but I would imagine as has
been the case for ages now with tk that this application is breaking
the ICCCM in some other way, and likely not even aware of it.

> With a bit of experimentation, I determined that using a style of:
>
> Style "SkyCat" !Icon
>
> the window no longer disappeared from all of the WindowLists anymore.

I suspect this a red herring, although it's interesting nevertheless.
When a given window is mapped, and it's determined to have no icon
name associated with it, it gets assigned a default value of
"Untitled" which is then set to the window name of the application if
possible.  This has no bearing on what's displayed in the windowlist
-- only a style of WindowListSkip would outright effect this.  Which
makes me suspect somehow this window is becoming unmanaged.

> Using other explicit icons did not help me in the same fashion.  Of
> course, the "Icon Name" property still remained blank except for that one
> host where some other part of the system set it to "SkyCat/IMG".
>
> Any ideas as to what might be going wrong?

Without running this program, no, and I don't have the time,
inclination or interest to even try since tk is a pain in the arse.  I
would personally use something like xscope at this point to intercept
the XEvents sent to this application so we can track what's happening
at each point.

-- Thomas Adam