When used with MiniBufExpl, Undotree won't load active file until I move back to it

[wolftune]

If undotree and https://github.com/fholgado/minibufexpl.vim are both installed, then opening undotree causes the cursor to be in the undotree buffer immediately, and that means the tree has no entries because it loads the wrong buffer. To make it work, I need to move back to the pane where the original file is.

[mbbill]

Confirmed.