Window layout broken by '<,'>Gitv!

[phmarek]

I'm using a vertically split layout, with two source files open.

Using '<,'>Gitv! to see changes in a range of lines works fine - the window is split, and the top half shows the commits.

But pressing on one of the commits closes the other source window!

Thanks for the nice feature, though!

[rbong]

This will require an overhaul of how gitv handles window switching. I'm holding off on this for now.