SYNOPSIS
--------
-'git merge-base' [--all] <commit> <commit>...
+[verse]
+'git merge-base' [-a|--all] [--octopus] <commit> <commit>...
+'git merge-base' --independent <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
ancestor', i.e. a 'merge base'. Note that there can be more than one
merge base for a pair of commits.
-Among the two commits to compute the merge base from, one is specified by
-the first commit argument on the command line; the other commit is a
-(possibly hypothetical) commit that is a merge across all the remaining
-commits on the command line. As the most common special case, specifying only
-two commits on the command line means computing the merge base between
-the given two commits.
+Unless `--octopus` is given, among the two commits to compute the merge
+base from, one is specified by the first commit argument on the command
+line; the other commit is a (possibly hypothetical) commit that is a merge
+across all the remaining commits on the command line. As the most common
+special case, specifying only 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.
+--octopus::
+ Compute the best common ancestors of all supplied commits,
+ in preparation for an n-way merge. This mimics the behavior
+ of 'git show-branch --merge-base'.
+
+--independent::
+ Instead of printing merge bases, print a minimal subset of
+ the supplied commits with the same ancestors. In other words,
+ among the commits given, list those which cannot be reached
+ from any other. This mimics the behavior of 'git show-branch
+ --independent'.
+
DISCUSSION
----------
--------------
Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
+See also
+--------
+linkgit:git-rev-list[1],
+linkgit:git-show-branch[1],
+linkgit:git-merge[1]
+
GIT
---
Part of the linkgit:git[1] suite