This is basically to confirm with small additions.
On Thu, Feb 13, 2020 at 02:19:42AM +0000, Aaron Sloman wrote:
> This came up as a side effect of my attempts to pin down the problems with
> popracer.
>
> This used to be a problem with motif/lesstif + an earlier version of 64bit
> poplog but I somehow thought it was no longer a problem in V16.
>
> To demonstrate the bug:
> (I think this should work with or without the Birmingham extensions.)
>
> The following should be done with and without linking in motif (see below).
>
> Run pop11
>
> then
>
> : uses rc_graphic;
> : rc_start();
>
> That should display an empty graphical window with label
> Xgraphic
>
> Use the kill-window button on the title bar (which will depend on which
> window manager you are using -- I use ctwm).
>
> If you have installed poplog linked with motif that will kill the window
> AND kill pop11. At least, that's what happens to me.
Yes, that happens to me to on Debian with Motif. I can add that
unlike previous Motif problem (which was actually a crash triggered
during handling Motif windows) this looks like effect of normal
Motif operation. That is Poplog calls Xt code to wait for events
and event handling code in Motif calls 'exit'.
> However, if I run pop11 with motif and open an XVed window, using the mouse
> to kill that window does not kill pop11 or any other windows opened by
> that poplog process.
>
> I.e. The effect is the same as simply quitting that file.
>
> Presumably that means that 64bit motif on linux has a feature in its text
> windows that should be in its non-text graphical windows but is missing,
> though it isn't missing in 32-bit motif graphical windows!
>
> You can unlink motif with this linux command
>
> $usepop/pop/src/newpop -link -x=-xt -norsv
>
> Then run pop11, as before
>
> : uses rc_graphic;
> : rc_start();
>
> Then kill the Xgraphic window with the mouse.
>
> That kills the window, but not the poplog process.
>
> Relink poplog with motif, if needed:
>
> $usepop/pop/src/newpop -link -x=-xm -norsv
>
> Unfortunately motif can be very useful, as pointed out earlier on this
> list.
>
> So this mal-feature in 64 bit motif is serious if it means graphical
> windows can be killed *safely* only by program commands, not by use of
> mouse.
>
> I wonder whether it affects only redhat versions of linux, or also others.
>
> I have searched online for reports of this bug but cannot find anything.
>
> Is there any way 64-bit poplog can *force* a motif object to hand
> interrupts to poplog instead of handling them itself, e.g. when the
> object is created, or does the motif library code have to be changed.
I have limited experience with X programming and almost no experience
with Motif. But I can say that basic design principle here is that
any thing which happens, happens as response to events and normally
user program, in this case Poplog can change even handling in
almost arbitrary ways. So, problem should be resolvable
entirely within Poplog. And solution is likely to be quite
simple, we just need to find it...
--
Waldek Hebisch
