Subject: [PATCH] pull: should be noop when already-up-to-date

From: "Erwin Villejo via GitGitGadget" <[email-masked]>
Date: Wed, 17 Nov 2021 07:55:50 +0000

From: Erwin Villejo <[email-masked]>

The already-up-to-date pull bug was fixed for --ff-only but it did not
include the case where --ff or --ff-only are not specified. This updates
the --ff-only fix to include the case where --ff or --ff-only are not
specified in command line flags or config.

Signed-off-by: Erwin Villejo <[email-masked]>
---
    pull: should be noop when already-up-to-date
    
    The already-up-to-date pull bug was fixed for --ff-only but it did not
    include the case where --ff or --ff-only are not specified. This updates
    the --ff-only fix to include the case where --ff or --ff-only are not
    specified in command line flags or config.
    
    Signed-off-by: Erwin Villejo [email-masked]

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1078%2Ferwinv%2Fmaster-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1078/erwinv/master-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1078

 builtin/pull.c               | 6 ++++--
 t/t7601-merge-pull-config.sh | 6 ++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/builtin/pull.c b/builtin/pull.c
index 127798ba84e..1cfaf9f3436 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -988,6 +988,7 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	struct object_id rebase_fork_point;
 	int rebase_unspecified = 0;
 	int can_ff;
+	int divergent;
 
 	if (!getenv("GIT_REFLOG_ACTION"))
 		set_reflog_message(argc, argv);
@@ -1102,15 +1103,16 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	}
 
 	can_ff = get_can_ff(&orig_head, &merge_heads);
+	divergent = !can_ff && !already_up_to_date(&orig_head, &merge_heads);
 
 	/* ff-only takes precedence over rebase */
 	if (opt_ff && !strcmp(opt_ff, "--ff-only")) {
-		if (!can_ff && !already_up_to_date(&orig_head, &merge_heads))
+		if (divergent)
 			die_ff_impossible();
 		opt_rebase = REBASE_FALSE;
 	}
 	/* If no action specified and we can't fast forward, then warn. */
-	if (!opt_ff && rebase_unspecified && !can_ff) {
+	if (!opt_ff && rebase_unspecified && divergent) {
 		show_advice_pull_non_ff();
 		die(_("Need to specify how to reconcile divergent branches."));
 	}
diff --git a/t/t7601-merge-pull-config.sh b/t/t7601-merge-pull-config.sh
index 6275641b9c2..bd238d89b0c 100755
--- a/t/t7601-merge-pull-config.sh
+++ b/t/t7601-merge-pull-config.sh
@@ -387,6 +387,12 @@ test_expect_success 'pull prevents non-fast-forward with "only" in pull.ff' '
 	test_must_fail git pull . c3
 '
 
+test_expect_success 'already-up-to-date pull succeeds with unspecified pull.ff' '
+	git reset --hard c1 &&
+	git pull . c0 &&
+	test "$(git rev-parse HEAD)" = "$(git rev-parse c1)"
+'
+
 test_expect_success 'already-up-to-date pull succeeds with "only" in pull.ff' '
 	git reset --hard c1 &&
 	test_config pull.ff only &&

base-commit: cd3e606211bb1cf8bc57f7d76bab98cc17a150bc
-- 
gitgitgadget