When going back to a single folder view in dolphin (by pressing F3 or by clicking on the Split button), the unfocussed window remains open, and the window which was in focus closes. It should ideally be the other way around
Steps to Reproduce:
1.Open dolphin to display any folder
2.Select split view (F3 or split button). select 2 different folders in the two panes.
3.Select any of the panes, say the left one
4. Hit F3 again or click Split to close the split view. The pane in focus (in this case. left pane) will close and the pane not in focus (in this case, right pane) will expand to occupy the entire dolphin view
Sometimes Dolphin crashes after this. Not always
Ideally pane in focus should remain open. and Dolphin shouldnt crash.
*** This bug has been marked as a duplicate of bug 312834 ***