spurious BadDrawable error when running test_tk

[Matthias Kievernagel]

Dear list,

I changed some detail in the tkinter library,
so I'm running the tk test like this:

./python -m test -u gui -v test_tk

Approximately every 2 or 3 runs I get a BadDrawable error
from the X server, most of the time at the end after
the last test finished successfully.
As this also happens when I run the test on the unmodified CPython sources
I suspect it is a shortcoming of my non-mainstream setup.
I use ctwm with interactive window placement,
so running the test involves a lot of clicks.
Does anyone know if the errors are to be expected
or should it work nonetheless?
I haven't found anything on b.p.o. about this.

Thanks for any insights,
Matthias Kievernagel