bulk-checkin: fix leaking state TODO

When flushing a bulk-checking to disk we also reset the `struct
bulk_checkin_packfile` state. But while we free some of its members,
others aren't being free'd, leading to memory leaks:

  - The temporary packfile name is not getting freed.

  - The `struct hashfile` only gets freed in case we end up calling
    `finalize_hashfile()`. There are code paths though where that is not
    the case, namely when nothing has been written. For this, we need to
    make `free_hashfile()` public.

Fix those leaks.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

bulk-checkin.c

@@ -61,6 +61,7 @@ static void flush_bulk_checkin_packfile(struct bulk_checkin_packfile *state)
 
 	if (state->nr_written == 0) {
 		close(state->f->fd);
+		free_hashfile(state->f);
 		unlink(state->pack_tmp_name);
 		goto clear_exit;
 	} else if (state->nr_written == 1) {
@@ -83,6 +84,7 @@ static void flush_bulk_checkin_packfile(struct bulk_checkin_packfile *state)
 		free(state->written[i]);
 
 clear_exit:
+	free(state->pack_tmp_name);
 	free(state->written);
 	memset(state, 0, sizeof(*state));
 

csum-file.c

@@ -56,7 +56,7 @@ void hashflush(struct hashfile *f)
 	}
 }
 
-static void free_hashfile(struct hashfile *f)
+void free_hashfile(struct hashfile *f)
 {
 	free(f->buffer);
 	free(f->check_buffer);

csum-file.h

@@ -46,6 +46,16 @@ int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *);
 struct hashfile *hashfd(int fd, const char *name);
 struct hashfile *hashfd_check(const char *name);
 struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp);
+
+/*
+ * Free the hashfile without flushing its contents to disk. This only
+ * needs to be called when not calling `finalize_hashfile()`.
+ */
+void free_hashfile(struct hashfile *f);
+
+/*
+ * Finalize the hashfile by flushing data to disk and free'ing it.
+ */
 int finalize_hashfile(struct hashfile *, unsigned char *, enum fsync_component, unsigned int);
 void hashwrite(struct hashfile *, const void *, unsigned int);
 void hashflush(struct hashfile *f);

t/t1050-large.sh

@@ -3,6 +3,7 @@
 
 test_description='adding and checking out large blobs'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'core.bigFileThreshold must be non-negative' '