[PATCH 1/5] t/helper/test-write-cache: clean up lock-handling

["Martin Ågren" <martin.agren@gmail.com>]

Die in case writing the index fails, so that the caller can notice
(instead of, say, being impressed by how performant the writing is).

While at it, note that after opening a lock with `LOCK_DIE_ON_ERROR`, we
do not need to worry about whether we succeeded. Also, we can move the
`struct lock_file` into the function and drop the staticness.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
---
 t/helper/test-write-cache.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/t/helper/test-write-cache.c b/t/helper/test-write-cache.c
index 017dc30380..8837717d36 100644
--- a/t/helper/test-write-cache.c
+++ b/t/helper/test-write-cache.c
@@ -2,22 +2,18 @@
 #include "cache.h"
 #include "lockfile.h"
 
-static struct lock_file index_lock;
-
 int cmd__write_cache(int argc, const char **argv)
 {
-	int i, cnt = 1, lockfd;
+	struct lock_file index_lock = LOCK_INIT;
+	int i, cnt = 1;
 	if (argc == 2)
 		cnt = strtol(argv[1], NULL, 0);
 	setup_git_directory();
 	read_cache();
 	for (i = 0; i < cnt; i++) {
-		lockfd = hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
-		if (0 <= lockfd) {
-			write_locked_index(&the_index, &index_lock, COMMIT_LOCK);
-		} else {
-			rollback_lock_file(&index_lock);
-		}
+		hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
+		if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
+			die("unable to write index file");
 	}
 
 	return 0;
-- 
2.17.0.411.g9fd64c8e46