Re: Issue with global config defaults "user.useConfigOnly = true" + "pull.rebase = preserve" - "user.email"

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> ... So I do think there may be a bug to be fixed,
> but it is simply commands being over-eager to make sure we have an
> ident when they might not need it.

36267854 (pull: fast-forward "pull --rebase=true", 2016-06-29) may
be a part of a good solution for that, perhaps?

-- >8 --
From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 29 Jun 2016 10:22:31 -0700
Subject: [PATCH] pull: fast-forward "pull --rebase=true"

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/pull.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/builtin/pull.c b/builtin/pull.c
index bf3fd3f..2a41d41 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -878,10 +878,24 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 		if (merge_heads.nr > 1)
 			die(_("Cannot merge multiple branches into empty head."));
 		return pull_into_void(*merge_heads.sha1, curr_head);
-	} else if (opt_rebase) {
-		if (merge_heads.nr > 1)
-			die(_("Cannot rebase onto multiple branches."));
+	}
+	if (opt_rebase && merge_heads.nr > 1)
+		die(_("Cannot rebase onto multiple branches."));
+
+	if (opt_rebase) {
+		struct commit_list *list = NULL;
+		struct commit *merge_head, *head;
+
+		head = lookup_commit_reference(orig_head);
+		commit_list_insert(head, &list);
+		merge_head = lookup_commit_reference(merge_heads.sha1[0]);
+		if (is_descendant_of(merge_head, list)) {
+			/* we can fast-forward this without invoking rebase */
+			opt_ff = "--ff-only";
+			return run_merge();
+		}
 		return run_rebase(curr_head, *merge_heads.sha1, rebase_fork_point);
-	} else
+	} else {
 		return run_merge();
+	}
 }
-- 
2.9.2-685-g483c9ea