From: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
If two 'git sparse-checkout set' subcommands are launched at the
same time, the behavior can be unexpected as they compete to write
the sparse-checkout file and update the working directory.
Take a lockfile around the writes to the sparse-checkout file. In
addition, acquire this lock around the working directory update
to avoid two commands updating the working directory in different
ways.
Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
---
builtin/sparse-checkout.c | 15 ++++++++++++---
t/t1091-sparse-checkout-builtin.sh | 7 +++++++
2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index 595955d4fc..b319966a79 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -305,6 +305,8 @@ static int write_patterns_and_update(struct pattern_list *pl)
{
char *sparse_filename;
FILE *fp;
+ int fd;
+ struct lock_file lk = LOCK_INIT;
int result;
if (!core_apply_sparse_checkout) {
@@ -314,21 +316,28 @@ static int write_patterns_and_update(struct pattern_list *pl)
result = update_working_directory(pl);
+ sparse_filename = get_sparse_checkout_filename();
+ fd = hold_lock_file_for_update(&lk, sparse_filename,
+ LOCK_DIE_ON_ERROR);
+
+ result = update_working_directory(pl);
if (result) {
+ rollback_lock_file(&lk);
+ free(sparse_filename);
clear_pattern_list(pl);
update_working_directory(NULL);
return result;
}
- sparse_filename = get_sparse_checkout_filename();
- fp = fopen(sparse_filename, "w");
+ fp = fdopen(fd, "w");
if (core_sparse_checkout_cone)
write_cone_to_file(fp, pl);
else
write_patterns_to_file(fp, pl);
- fclose(fp);
+ fflush(fp);
+ commit_lock_file(&lk);
free(sparse_filename);
clear_pattern_list(pl);
diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index ecb5a63671..48493e1012 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -262,4 +262,11 @@ test_expect_success 'revert to old sparse-checkout on bad update' '
test_cmp dir expect
'
+test_expect_success 'fail when lock is taken' '
+ test_when_finished rm -rf repo/.git/info/sparse-checkout.lock &&
+ touch repo/.git/info/sparse-checkout.lock &&
+ test_must_fail git -C repo sparse-checkout set deep 2>err &&
+ test_i18ngrep "File exists" err
+'
+
test_done
--
gitgitgadget
