I cut a 3/4" strip out of the wall and moved it to the open edge of the doorway. Voila! a "real" doorway. The crossbars are just bracing while the glue dries, and some reinforcement will be added at the joint. I'm going to put channel over the edge, so that will help stablize the joint, too.
The wall really is square. The camera made it look a bit bowed.