Closing the first tab will show an empty GraphEdit

[RailKill]

Version: 2.2.2
Severity: Low

Steps to Reproduce

1. Open two files.
2. Close the first tab.

Current Behavior

After closing the first tab, even though a second tab exists, it will not show the graph until the user clicks on the tab.

Expected Behavior

It should switch to the second tab. It works if the user closes the second tab; Monologue will switch to the first. But if the user closes the first, it would not switch to the second.