Use 'merge-base --all' where applicable.

It may get extra merge base on truly pathological commit histories,
but is a lot easier to understand, explain, and prove correctness.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/git-merge.sh b/git-merge.sh
index b810fce..7f481e4 100755 (executable)
--- a/git-merge.sh
+++ b/git-merge.sh
@@ -110,7 +110,14 @@ do
            die "$remote - not something we can merge"
 done
 
-common=$(git-show-branch --merge-base $head "$@")
+case "$#" in
+1)
+       common=$(git-merge-base --all $head "$@")
+       ;;
+*)
+       common=$(git-show-branch --merge-base $head "$@")
+       ;;
+esac
 echo "$head" >"$GIT_DIR/ORIG_HEAD"
 
 case "$#,$common,$no_commit" in
@@ -162,7 +169,7 @@ case "$#,$common,$no_commit" in
        up_to_date=t
        for remote
        do
-               common_one=$(git-merge-base $head $remote)
+               common_one=$(git-merge-base --all $head $remote)
                if test "$common_one" != "$remote"
                then
                        up_to_date=f