[PATCH] cherry-pick: do not error on non-merge commits when '-m 1' is specified

[Sergey Organov <sorganov@gmail.com>]

When cherry-picking multiple commits, it's impossible to have both
merge- and non-merge commits on the same command-line. Not specifying
'-m 1' results in cherry-pick refusing to handle merge commits, while
specifying '-m 1' fails on non-merge commits.

This patch allows '-m 1' for non-merge commits. Besides, as mainline is
always the only parent for a non-merge commit, it made little sense to
disable it in the first place.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
---
 sequencer.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 1ce6326..2393bdf 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1543,9 +1543,11 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 			return error(_("commit %s does not have parent %d"),
 				oid_to_hex(&commit->object.oid), opts->mainline);
 		parent = p->item;
-	} else if (0 < opts->mainline)
-		return error(_("mainline was specified but commit %s is not a merge."),
-			oid_to_hex(&commit->object.oid));
+	} else if (1 < opts->mainline)
+		/* Non-first parent explicitly specified as mainline for
+		 * non-merge commit */
+		return error(_("commit %s does not have parent %d"),
+			     oid_to_hex(&commit->object.oid), opts->mainline);
 	else
 		parent = commit->parents->item;
 
-- 
2.10.0.1.g57b01a3