On Sat, Jan 04, 2014 at 09:40:16AM +0100, Frank Fischer wrote:
Am 04.01.2014 02:13, schrieb Linus Arver:
My problem is that undo-tree is loaded, but disabled when I open a file with an unrecognized extension (e.g., a file named "foo", but not "foo.txt").
Again, the strange thing is that undo-tree is enabled on the *Messages* buffer, but disabled (turned off) in the "foo" buffer.
This is expected. Undo-tree (like Evil) is a minor-mode that is automatically enabled in each buffer if the corresponding "globalized minor mode" (namely global-undo-tree-mode) is enabled. This is realised by some special change-major-mode-hook and after-change-major-mode-hook hooks. However, if a new buffer is started in fundamental-mode these hooks are not run (in contrast to any other major-mode), that's why the local undo-tree-mode never gets a chance to be activated. The same is true for Evil.
However, unlike undo-tree Evil adds a few additional hacks to overcome this problem. That's why Evil gets activated in fundamental-mode buffers and undo-tree does not.
So if you want undo-tree to be enabled in all buffers in which Evil is enabled, the simplest solution is probably to do so directly:
(add-hook 'evil-local-mode-hook 'turn-on-undo-tree-mode)
Thank you very much for the explanation. I just tested your line of code and undo-tree does get enabled in new buffers. I'm starting to think now that this should be the default Evil behavior, as Evil requires undo-tree to function properly (i.e., it does not make sense to have Evil enabled without undo-tree-mode, when undo-tree is available). -L