Re: Merge-base alias for git vc-diff

[Juri Linkov]

>> And also add a new command that would use it, similar to
>> vc-root-version-diff (or a new meaning to some value of the prefix
>> argument).
>
> Adding a new command like ‘vc-merge-base-diff’ is easy, but first
> I'd like to try to extend the existing command because it is bound
> to a short key sequence: ‘C-u C-x v D’ then type ‘TAB’ for completion
> and select e.g. ‘MERGE-BASE’.

Since there is no good solution to reuse the existing command,
bug#33950 implements two new commands:

* vc-log-mergebase (bound to ‘C-x v M L’) shows the same output as
  GitLab shows in the “Commits” tab of the merge request.

* vc-diff-mergebase (bound to ‘C-x v M D’) shows the same output as
  GitLab shows in the “Changes” tab of the merge request.