[PATCH 2/2] maintenance: trigger --auto for promisor rollups

[Taylor Blau <ttaylorr@openai.com>]

Commit 9bc151850c (builtin/maintenance: introduce "geometric-repack"
task, 2025-10-24) added an auto condition for the geometric-repack
task. It runs the task when ordinary packs need to be combined or when
the number of loose objects crosses the configured threshold.

Later on in commit dcc9c7ef47 (builtin/repack: handle promisor packs
with geometric repacking, 2026-01-05), the geometric repack machinery
started handling promisor packs separately, but did not correspondingly
update the auto condition.

As a result, a repository can have promisor packs ready to combine
while its non-promisor packs and loose object count require no work. In
that case, `--auto` skips the task even though a geometric repack
would combine at least two promisor packs.

Check `geometry.promisor_split` alongside `geometry.split`.

There is some fallout in t5331: the new condition makes a filtered
clone eligible for auto-maintenance before the test inspects its
promisor packs. Disable auto-maintenance in that fixture so it
continues to test `--stdin-packs`, not the maintenance task.

Signed-off-by: Taylor Blau <ttaylorr@openai.com>
---
 builtin/gc.c                  |  2 +-
 t/t5331-pack-objects-stdin.sh |  3 ++-
 t/t7900-maintenance.sh        | 23 +++++++++++++++++++++++
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/builtin/gc.c b/builtin/gc.c
index ed75c12c43..e9572940dc 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -1649,7 +1649,7 @@ static int geometric_repack_auto_condition(struct gc_config *cfg UNUSED)
 	 * When we'd merge at least two packs with one another we always
 	 * perform the repack.
 	 */
-	if (geometry.split) {
+	if (geometry.split || geometry.promisor_split) {
 		ret = 1;
 		goto out;
 	}
diff --git a/t/t5331-pack-objects-stdin.sh b/t/t5331-pack-objects-stdin.sh
index c74b5861af..2a983e28ac 100755
--- a/t/t5331-pack-objects-stdin.sh
+++ b/t/t5331-pack-objects-stdin.sh
@@ -368,7 +368,8 @@ test_expect_success '--stdin-packs does not perform backfill fetch' '
 	git -C remote config set --local uploadpack.allowfilter 1 &&
 	git -C remote config set --local uploadpack.allowanysha1inwant 1 &&
 
-	git clone --filter=tree:0 "file://$(pwd)/remote" client &&
+	git -c maintenance.auto=false clone --filter=tree:0 \
+		"file://$(pwd)/remote" client &&
 	(
 		cd client &&
 		ls .git/objects/pack/*.promisor | sed "s|.*/||; s/\.promisor$/.pack/" >packs &&
diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
index ba5b359e77..fb5f2d8902 100755
--- a/t/t7900-maintenance.sh
+++ b/t/t7900-maintenance.sh
@@ -759,6 +759,29 @@ test_expect_success 'geometric repacking with --auto' '
 	)
 '
 
+test_expect_success 'geometric repacking with --auto handles promisor packs' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		git config set maintenance.auto false &&
+		git remote add promisor garbage &&
+		git config set remote.promisor.promisor true &&
+
+		for n in $(test_seq 6)
+		do
+			test_commit $n || return 1
+		done &&
+
+		pack_promisor 1 >/dev/null &&
+		pack_promisor 1..2 >/dev/null &&
+		pack_promisor 2..6 >/dev/null &&
+		git prune-packed &&
+
+		test_geometric_repack_needed true auto=9000
+	)
+'
+
 test_expect_success 'geometric repacking honors configured split factor' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
-- 
2.55.0.483.gdc2fffc37c