DestroyNotify: thread blocked indefinitely in an STM transaction

[jchnkl]

I get repeatable BlockedIndefinitelyOnSTM exceptions whenever a client exits and a DestroyNotify event is issued.
Edit:
The error happens only if the window which generates the DestroyNotify event had its focus set with SetInputFocus. If then a request (e.g. ConfigureWindow) is issued prior to the DestroyNotify event, e.g. in response to a LeaveNotify event on the now non-existing window, the error will occur.

Edit 2:
As a workaround I've getInputFocus c >>= void . getReply in the LeaveNotify event handler. Now the error doesn't occur anymore.