Infinite segfault loop on closing event display window

[dennisklein]

OS: Fedora 31 Compiler: GCC 10.2.1 FairRoot: dev @ 71dedec0fbeee1ff0a093709a6916c11663951f5

When closing the event display window by clicking the X in the top right corner, one ends up in an infinite segfault loop:

Root >   
 *** Break *** segmentation violation
Root >
 *** Break *** segmentation violation
Root >
 *** Break *** segmentation violation
Root >
 *** Break *** segmentation violation
Root >
 *** Break *** segmentation violation
Root >
...                                

OTOH, exiting by closing the root session with .q works.

[DanielWielanek]

Hi, I think I found solution. But honestly I could not find the real source of the problem - I just change code as long as this error wanished.

[ChristianTackeGSI]

Just to link the PR: #1150