[PATCH/resend] Documentation: update to git-merge-base --octopus

[Vincent van Ravesteijn <vfr@lyx.org>]

1) Make it clear that when the --octopus parameter is given to 'git merge-base',
only a set of commits is expected as the parameter. On the other hand, in the
case without the --octopus parameter, it is necessary to supply a single commit
and a set. Moreover, in the case of --octopus merging, a single commit is also valid,
which is not the case otherwise.

2) Add a sentence to the discussion that when --octopus is used, we do expect '2'
as the result.

Signed-off-by: Vincent van Ravesteijn <vfr@lyx.org>
---
Sorry for the noise caused by the previous attempt(s). Apparently my attempts
to let Thunderbird _not wrap_ the lines were counterproductive.

Here is the patch again.

 Documentation/git-merge-base.txt |    6 +++++-
 builtin/merge-base.c             |    3 ++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/Documentation/git-merge-base.txt b/Documentation/git-merge-base.txt
index eedef1b..1bac04f 100644
--- a/Documentation/git-merge-base.txt
+++ b/Documentation/git-merge-base.txt
@@ -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
@@ -89,6 +90,9 @@ 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.

+When the option `--octopus` is given, the result of `git merge-base A B C`
+will be '2', because '2' is the common ancestor of all branches.
+
 When the history involves criss-cross merges, there can be more than one
 'best' common ancestor for two commits.  For example, with this topology:

diff --git a/builtin/merge-base.c b/builtin/merge-base.c
index 96dd160..4f30f1b 100644
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@ -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
 };
-- 
1.7.3.1.msysgit.0