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-rw-r--r--Documentation/git-merge-base.txt46
1 files changed, 33 insertions, 13 deletions
diff --git a/Documentation/git-merge-base.txt b/Documentation/git-merge-base.txt
index ce5b369985..b295bf8330 100644
--- a/Documentation/git-merge-base.txt
+++ b/Documentation/git-merge-base.txt
@@ -8,7 +8,10 @@ git-merge-base - Find as good common ancestors as possible for a merge
SYNOPSIS
--------
+[verse]
'git merge-base' [-a|--all] <commit> <commit>...
+'git merge-base' [-a|--all] --octopus <commit>...
+'git merge-base' --independent <commit>...
DESCRIPTION
-----------
@@ -20,17 +23,33 @@ 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.
+OPERATION MODE
+--------------
+
+As the most common special case, specifying only two commits on the
+command line means computing the merge base between the given two commits.
+
+More generally, 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 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.
+--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'.
+
OPTIONS
-------
-a::
@@ -75,6 +94,9 @@ 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.
+The result of `git merge-base --octopus A B C` is '2', because '2' is
+the best common ancestor of all commits.
+
When the history involves criss-cross merges, there can be more than one
'best' common ancestor for two commits. For example, with this topology:
@@ -88,13 +110,11 @@ 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>.
+See also
+--------
+linkgit:git-rev-list[1],
+linkgit:git-show-branch[1],
+linkgit:git-merge[1]
GIT
---