Diff of current and previous version using vim-fugitive

I believe it is as simple as:

:vert diffsplit #

This is what I use:

:Gdiff [revision]

See :help Gdiff for other options as well (vertical vs horizontal splits, etc).

For example:

:Gdiff HEAD

or if you have a revision number (ie: aaffdfdstsdgssetds):

:Gdiff aaffdfds

Could not get fugitive to do what I want (it either doesn't do it or I don't know how to use it), but I did find the plugin which gives the desired behaviour: https://github.com/kablamo/vim-git-log.

(it does not show the diff in quickfix list but in a full sized buffer, which is OK)

First, open the file you want to diff with.

If the change is committed, enter :Gdiff HEAD~1.
If the change is NOT committed, enter :Gdiff HEAD.