зеркало из https://github.com/microsoft/git.git
102 строки
2.9 KiB
Plaintext
102 строки
2.9 KiB
Plaintext
git-merge-base(1)
|
|
=================
|
|
|
|
NAME
|
|
----
|
|
git-merge-base - Find as good common ancestors as possible for a merge
|
|
|
|
|
|
SYNOPSIS
|
|
--------
|
|
'git merge-base' [-a|--all] <commit> <commit>...
|
|
|
|
DESCRIPTION
|
|
-----------
|
|
|
|
'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.
|
|
|
|
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.
|
|
|
|
DISCUSSION
|
|
----------
|
|
|
|
Given two commits 'A' and 'B', `git merge-base A B` will output a commit
|
|
which is reachable from both 'A' and 'B' through the parent relationship.
|
|
|
|
For example, with this topology:
|
|
|
|
o---o---o---B
|
|
/
|
|
---o---1---o---o---o---A
|
|
|
|
the merge base between 'A' and 'B' is '1'.
|
|
|
|
Given three commits 'A', 'B' and 'C', `git merge-base A B C` will compute the
|
|
merge base between 'A' and a hypothetical commit 'M', which is a merge
|
|
between 'B' and 'C'. For example, with this topology:
|
|
|
|
o---o---o---o---C
|
|
/
|
|
/ o---o---o---B
|
|
/ /
|
|
---2---1---o---o---o---A
|
|
|
|
the result of `git merge-base A B C` is '1'. This is because the
|
|
equivalent topology with a merge commit 'M' between 'B' and 'C' is:
|
|
|
|
|
|
o---o---o---o---o
|
|
/ \
|
|
/ o---o---o---o---M
|
|
/ /
|
|
---2---1---o---o---o---A
|
|
|
|
and the result of `git merge-base A M` is '1'. Commit '2' is also a
|
|
common ancestor between 'A' and 'M', but '1' is a better common ancestor,
|
|
because '2' is an ancestor of '1'. Hence, '2' is not a merge base.
|
|
|
|
When the history involves criss-cross merges, there can be more than one
|
|
'best' common ancestor for two commits. For example, with this topology:
|
|
|
|
---1---o---A
|
|
\ /
|
|
X
|
|
/ \
|
|
---2---o---o---B
|
|
|
|
both '1' and '2' are merge-bases of A and B. Neither one is better than
|
|
the other (both are 'best' merge bases). When the `--all` option is not given,
|
|
it is unspecified which best one is output.
|
|
|
|
Author
|
|
------
|
|
Written by Linus Torvalds <torvalds@osdl.org>
|
|
|
|
Documentation
|
|
--------------
|
|
Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
|
|
|
|
GIT
|
|
---
|
|
Part of the linkgit:git[1] suite
|