[PATCH] files_initial_transaction_commit(): only unlock if locked

[Mathias Rav]

Running git clone --single-branch --mirror -b TAGNAME previously
triggered the following error message:

        fatal: multiple updates for ref 'refs/tags/TAGNAME' not allowed.

This error condition is handled in files_initial_transaction_commit().

42c7f7ff9 ("commit_packed_refs(): remove call to `packed_refs_unlock()`", 
2017-06-23)
introduced incorrect unlocking in the error path of this function,
which changes the error message to

        fatal: BUG: packed_refs_unlock() called when not locked

Move the call to packed_refs_unlock() above the "cleanup:" label
since the unlocking should only be done in the last error path.

Signed-off-by: Mathias Rav <m...@git.strova.dk>
---
 refs/files-backend.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/refs/files-backend.c b/refs/files-backend.c
index a80d60aa0..afe5c4e94 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2874,13 +2874,12 @@ static int files_initial_transaction_commit(struct 
ref_store *ref_store,
 
        if (initial_ref_transaction_commit(packed_transaction, err)) {
                ret = TRANSACTION_GENERIC_ERROR;
-               goto cleanup;
        }
 
+       packed_refs_unlock(refs->packed_ref_store);
 cleanup:
        if (packed_transaction)
                ref_transaction_free(packed_transaction);
-       packed_refs_unlock(refs->packed_ref_store);
        transaction->state = REF_TRANSACTION_CLOSED;
        string_list_clear(&affected_refnames, 0);
        return ret;
-- 
2.15.1