Behavior editor hangs during state machine layout

An infinite loop during initial layout of a state machine was encountered. See attached ROOM model example.room. According to author, the state machine was created in the graphical behavior editor, and then the .room model was copied to a different project on its own without the corresponding diagram.

On debugging, looks like in DiagramEditingUtil.getPositions(), transition "tr9" ends up twice in the taskList while nodesToPlace remains empty, which causes an infinite loop. Removing "tr9" from the state machine solves the infinite loop.