> What, you mean neither of the display corruptions happen with the
 > above breakpoint active?  Then it sounds like we have some timing or
 > race condition problems, and debugging this will be very hard indeed.

Debugging this way extremely slows down movement in the menu.

 > Let's try to see the problem from the other end.  Please do:
 >
 >   M-x open-termscript RET SOME-FILE RET
 >
 > then hit F10, type C-n and/or C-p several times, make sure the problem
 > happens, then exit Emacs and then post SOME-FILE.

Attached as ts.txt.

 > (Btw, this warrants a bug filed long ago.  So please do, and let's
 > continue there.)

I'm already quite confused with the present TTY threads so please let's
postpone that unless you consider it utterly necessary.

martin