[PATCH] update-ref: Handle large transactions properly

Test if we can do arbitrary large transactions. Currently this is a known
bug that we cannot do large transactions, so document it at least in the
test suite.

Signed-off-by: Stefan Beller <redacted>
---
 t/t1400-update-ref.sh | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index 6805b9e..a7dd1ff 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh

@@ -1065,4 +1065,31 @@ test_expect_success 'stdin -z delete refs works with packed and loose refs' '
        test_must_fail git rev-parse --verify -q $c
 '

+run_with_limited_open_files () {
+       (ulimit -n 64 && "$@")
+}
+
+test_lazy_prereq ULIMIT 'run_with_limited_open_files true'
+
+test_expect_failure ULIMIT 'large transaction creating branches does not burst open file limit' '
+(
+       for i in $(seq 65)
+               echo "create refs/heads/$i HEAD"
+       done >large_input &&
+       git update-ref --stdin <large_input &&
+       git rev-parse --verify -q refs/heads/65
+)
+'
+
+test_expect_failure ULIMIT 'large transaction deleting branches does not burst open file limit' '
+(
+       for i in $(seq 33)