[RFC PATCH 31/35] pull: improve --rebase and pull.rebase interaction

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

Currently --rebase without argument overrides pull.rebase:

  git config pull.rebase merges
  git pull --rebase

Up until now this hasn't been a big issue, since user has not been
forced to specify a merge, or a rebase. But with the introduction of
--merge and pull.mode, the user could in theory have the following
configuration:

  git config pull.mode merge
  git config pull.rebase merges

In such case, the user would expect:

  git pull --rebase

To be the same as:

  git pull --rebase=merges

If the user wants to override the configuration, she can do:

  git pull --rebase=true

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
---
 builtin/pull.c  | 10 ++++++++--
 t/t5520-pull.sh | 10 ++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/builtin/pull.c b/builtin/pull.c
index f4f822700a..e304b22bd8 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -68,8 +68,14 @@ static int parse_opt_rebase(const struct option *opt, const char *arg, int unset
 
 	if (arg)
 		*value = parse_config_rebase("--rebase", arg, 0);
-	else
-		*value = unset ? REBASE_FALSE : REBASE_TRUE;
+	else {
+		if (!unset) {
+			/* --rebase shouldn't override pull.rebase=merges (and others) */
+			if (*value < REBASE_TRUE)
+				*value = REBASE_TRUE;
+		} else
+			*value = REBASE_FALSE;
+	}
 
 	if (*value > 0)
 		mode = *value >= REBASE_TRUE ? PULL_MODE_REBASE : PULL_MODE_MERGE;
diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index 7ea558651d..b3b70d145f 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh
@@ -597,6 +597,16 @@ test_expect_success REBASE_P \
 	test_cmp_rev HEAD^2 keep-merge
 '
 
+test_expect_success REBASE_P \
+	'pull.rebase=preserve interacts correctly with pull.mode and --rebase' '
+	git reset --hard before-preserve-rebase &&
+	test_config pull.mode merge &&
+	test_config pull.rebase preserve &&
+	git pull --rebase . copy &&
+	test_cmp_rev HEAD^^ copy &&
+	test_cmp_rev HEAD^2 keep-merge
+'
+
 test_expect_success 'pull.rebase=interactive' '
 	write_script "$TRASH_DIRECTORY/fake-editor" <<-\EOF &&
 	echo I was here >fake.out &&
-- 
2.32.0.36.g70aac2b1aa