[RFC PATCH 19/35] pull: cleanup autostash check

[Felipe Contreras <felipe.contreras@gmail.com>]

Currently "git pull --rebase" takes a shortcut in the case a
fast-forward merge is possible; run_merge() is called with --ff-only.

However, "git merge" didn't have an --autostash option, so, when "git
pull --rebase --autostash" was called *and* the fast-forward merge
shortcut was taken, then the pull failed.

This was fixed in commit f15e7cf5cc (pull: ff --rebase --autostash
works in dirty repo, 2017-06-01) by simply skipping the fast-forward
merge shortcut.

Later on "git merge" learned the --autostash option [a03b55530a
(merge: teach --autostash option, 2020-04-07)], and so did "git pull"
[d9f15d37f1 (pull: pass --autostash to merge, 2020-04-07)].

Therefore it's not necessary to skip the fast-forward merge shortcut
anymore when called with --rebase --autostash.

Let's always take the fast-forward merge shortcut by essentially
reverting f15e7cf5cc.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
---
 builtin/pull.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/builtin/pull.c b/builtin/pull.c
index e8927fc2ff..a22293b7db 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -947,7 +947,6 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	struct oid_array merge_heads = OID_ARRAY_INIT;
 	struct object_id orig_head, curr_head;
 	struct object_id rebase_fork_point;
-	int autostash;
 	int rebase_unspecified = 0;
 	int can_ff;
 
@@ -982,8 +981,8 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	if (get_oid("HEAD", &orig_head))
 		oidclr(&orig_head);
 
-	autostash = config_autostash;
 	if (opt_rebase) {
+		int autostash = config_autostash;
 		if (opt_autostash != -1)
 			autostash = opt_autostash;
 
@@ -1065,13 +1064,12 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 		     recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
 		    submodule_touches_in_range(the_repository, &upstream, &curr_head))
 			die(_("cannot rebase with locally recorded submodule modifications"));
-		if (!autostash) {
-			if (can_ff) {
-				/* we can fast-forward this without invoking rebase */
-				opt_ff = "--ff-only";
-				ran_ff = 1;
-				ret = run_merge();
-			}
+
+		if (can_ff) {
+			/* we can fast-forward this without invoking rebase */
+			opt_ff = "--ff-only";
+			ran_ff = 1;
+			ret = run_merge();
 		}
 		if (!ran_ff)
 			ret = run_rebase(&newbase, &upstream);
-- 
2.32.0.36.g70aac2b1aa