#166 closing CSL reduce window with button result in segfault

[arpi]

Often, after running a longer calculation (reading it from a file), if I click the close button of the CSL reduce window, I get the error message
event_flag = ffffff08
Fatal error attempting to write to a pipe

~~~ SIGNAL ~~~: SIGSEGV
and the window starts to not respond. Reduce needs then to be killed with a kill signal (-9).