Merge branch 'vr/merge-base-doc'

* vr/merge-base-doc:
  Restructure documentation for git-merge-base.
  Documentation: update to git-merge-base --octopus
This commit is contained in:
Junio C Hamano 2011-05-04 15:51:37 -07:00
commit 014d298b1d
2 changed files with 23 additions and 14 deletions

View file

@ -9,7 +9,8 @@ git-merge-base - Find as good common ancestors as possible for a merge
SYNOPSIS
--------
[verse]
'git merge-base' [-a|--all] [--octopus] <commit> <commit>...
'git merge-base' [-a|--all] <commit> <commit>...
'git merge-base' [-a|--all] --octopus <commit>...
'git merge-base' --independent <commit>...
DESCRIPTION
@ -22,23 +23,21 @@ 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.
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.
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.
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
@ -51,6 +50,12 @@ OPTIONS
from any other. This mimics the behavior of 'git show-branch
--independent'.
OPTIONS
-------
-a::
--all::
Output all merge bases for the commits, instead of just one.
DISCUSSION
----------
@ -89,6 +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:

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@ -23,7 +23,8 @@ static int show_merge_base(struct commit **rev, int rev_nr, int show_all)
}
static const char * const merge_base_usage[] = {
"git merge-base [-a|--all] [--octopus] <commit> <commit>...",
"git merge-base [-a|--all] <commit> <commit>...",
"git merge-base [-a|--all] --octopus <commit>...",
"git merge-base --independent <commit>...",
NULL
};