I have now managed to reproduce this bug.

Delete ~/.es directory.
Start estudio and compile sample non-graphical application.
Click on Maximize button in the single Editor tab.
Click on the "X" for single Editor tab to close it.
Exit estudio.
Restart estudio.  Click Cancel.  Select File/Exit.  Estudio
crashes with seg fault in `parent' called from {SD_MULTI_DOCK_AREA}.editor_parent.
Trace previously attached.