SYNOPSIS
--------
-'git merge-base' [--all] <commit> <commit>...
+'git merge-base' [-a|--all] <commit> <commit>...
DESCRIPTION
-----------
-'git-merge-base' finds best common ancestor(s) between two commits to use
+'git merge-base' finds best common ancestor(s) between two commits to use
in a three-way merge. One common ancestor is 'better' than another common
ancestor if the latter is an ancestor of the former. A common ancestor
that does not have any better common ancestor is a 'best common
two commits on the command line means computing the merge base between
the given two commits.
+As a consequence, the 'merge base' is not necessarily contained in each of the
+commit arguments if more than two commits are specified. This is different
+from linkgit:git-show-branch[1] when used with the `--merge-base` option.
+
OPTIONS
-------
+-a::
--all::
Output all merge bases for the commits, instead of just one.