sparse-checkout: check commit_lock_file when writing patterns

When writing a new "sparse-checkout" file, we do the usual strategy of
writing to a lockfile and committing it into place. But we don't check
the outcome of commit_lock_file(). Failing there would prevent us from
writing a bogus file (good), but we would ignore the error and return a
successful exit code (bad).

Fix this by calling die(). Note that we need to keep the sparse_filename
variable valid for longer, since the filename stored in the lock_file
struct will be dropped when we run commit_lock_file().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index dfefe609a1a6adc504e4e91c694c435c7197104c..b5e220cc445e6f38e5eaf3ed0ed419c1ec226eae 100644 (file)
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -338,7 +338,6 @@ static int write_patterns_and_update(struct pattern_list *pl)
 
        fd = hold_lock_file_for_update(&lk, sparse_filename,
                                      LOCK_DIE_ON_ERROR);
-       free(sparse_filename);
 
        result = update_working_directory(pl);
        if (result) {
@@ -355,10 +354,12 @@ static int write_patterns_and_update(struct pattern_list *pl)
                write_patterns_to_file(fp, pl);
 
        fflush(fp);
-       commit_lock_file(&lk);
+       if (commit_lock_file(&lk))
+               die_errno(_("unable to write %s"), sparse_filename);
 
 out:
        clear_pattern_list(pl);
+       free(sparse_filename);
        return result;
 }