subtree: force merge commit

When `merge.ff` is set to `only` in .gitconfig, `git subtree pull` will
fail with error `fatal: Not possible to fast-forward, aborting.`, but
the command does want to make merges in these places. Add `--no-ff`
argument to `git merge` to enforce this behaviour.

Signed-off-by: Thomas Koutcher <redacted>
Reviewed-by: Johannes Altmanninger <redacted>
Signed-off-by: Junio C Hamano <redacted>

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index 71f1fd94bde8b0cd1653677612b0f21e5b36bcd4..1af1d9653e94b39623f8435957c6e7537c41c60a 100755 (executable)
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -975,10 +975,10 @@ cmd_merge () {
 
        if test -n "$arg_addmerge_message"
        then
-               git merge -Xsubtree="$arg_prefix" \
+               git merge --no-ff -Xsubtree="$arg_prefix" \
                        --message="$arg_addmerge_message" "$rev"
        else
-               git merge -Xsubtree="$arg_prefix" $rev
+               git merge --no-ff -Xsubtree="$arg_prefix" $rev
        fi
 }