subtree: allow --squash to be used with --rejoin

Besides being a genuinely useful thing to do, this also just makes sense
and harmonizes which flags may be used when.  `git subtree split
--rejoin` amounts to "automatically go ahead and do a `git subtree
merge` after doing the main `git subtree split`", so it's weird and
arbitrary that you can't pass `--squash` to `git subtree split --rejoin`
like you can `git subtree merge`.  It's weird that `git subtree split
--rejoin` inherits `git subtree merge`'s `--message` but not `--squash`.

Reconcile the situation by just having `split --rejoin` actually just
call `merge` internally (or call `add` instead, as appropriate), so it
can get access to the full `merge` behavior, including `--squash`.

Signed-off-by: Luke Shumaker <lukeshu@datawire.io>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/contrib/subtree/t/t7900-subtree.sh b/contrib/subtree/t/t7900-subtree.sh
index ce6861c22d..2561e25f43 100755
--- a/contrib/subtree/t/t7900-subtree.sh
+++ b/contrib/subtree/t/t7900-subtree.sh
@@ -324,6 +324,62 @@ test_expect_success 'split sub dir/ with --rejoin and --message' '
 	)
 '
 
+test_expect_success 'split "sub dir"/ with --rejoin and --squash' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" --squash FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git subtree pull --prefix="sub dir" --squash ./"sub proj" HEAD &&
+		MAIN=$(git rev-parse --verify HEAD) &&
+		SUB=$(git -C "sub proj" rev-parse --verify HEAD) &&
+
+		SPLIT=$(git subtree split --prefix="sub dir" --annotate="*" --rejoin --squash) &&
+
+		test_must_fail git merge-base --is-ancestor $SUB HEAD &&
+		test_must_fail git merge-base --is-ancestor $SPLIT HEAD &&
+		git rev-list HEAD ^$MAIN >commit-list &&
+		test_line_count = 2 commit-list &&
+		test "$(git rev-parse --verify HEAD:)"           = "$(git rev-parse --verify $MAIN:)" &&
+		test "$(git rev-parse --verify HEAD:"sub dir")"  = "$(git rev-parse --verify $SPLIT:)" &&
+		test "$(git rev-parse --verify HEAD^1)"          = $MAIN &&
+		test "$(git rev-parse --verify HEAD^2)"         != $SPLIT &&
+		test "$(git rev-parse --verify HEAD^2:)"         = "$(git rev-parse --verify $SPLIT:)" &&
+		test "$(last_commit_subject)" = "Split '\''sub dir/'\'' into commit '\''$SPLIT'\''"
+	)
+'
+
+test_expect_success 'split then pull "sub dir"/ with --rejoin and --squash' '
+	# 1. "add"
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	git -C "$test_count" subtree --prefix="sub dir" add --squash ./"sub proj" HEAD &&
+
+	# 2. commit from parent
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+
+	# 3. "split --rejoin --squash"
+	git -C "$test_count" subtree --prefix="sub dir" split --rejoin --squash &&
+
+	# 4. "pull --squash"
+	test_create_commit "$test_count/sub proj" sub2 &&
+	git -C "$test_count" subtree -d --prefix="sub dir" pull --squash ./"sub proj" HEAD &&
+
+	test_must_fail git merge-base HEAD FETCH_HEAD
+'
+
 test_expect_success 'split "sub dir"/ with --branch' '
 	subtree_test_create_repo "$test_count" &&
 	subtree_test_create_repo "$test_count/sub proj" &&