[PATCH v2] http: fix memory leak in fetch_and_setup_pack_index()

[LorenzoPegorari <lorenzo.pegorari2002@gmail.com>]

Inside the function `fetch_and_setup_pack_index()`, when the pack
obtained using `parse_pack_index()` fails to be verified by
`verify_pack_index()`, the function returns without closing and freeing
said pack.

Fix this by calling `close_pack_index()` to munmap the index file for
the leaking pack (which might have been mmapped by `fetch_pack_index()`
or `verify_pack_index()`), and then free it, when the verification
fails.

Also, do some more cleanup by removing the useless call to the function
`unlink()`. This is not necessary anymore since 63aca3f7f1 (dumb-http:
store downloaded pack idx as tempfile, 2024-10-25), when
`fetch_pack_index()` started registering its return value (in this case
`tmp_idx`) as a tempfile to be deleted at process exit.

Signed-off-by: LorenzoPegorari <lorenzo.pegorari2002@gmail.com>
---
 http.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/http.c b/http.c
index 67c9c6fc60..99da4d7529 100644
--- a/http.c
+++ b/http.c
@@ -2538,18 +2538,18 @@ static int fetch_and_setup_pack_index(struct packfile_list *packs,
 
 	new_pack = parse_pack_index(the_repository, sha1, tmp_idx);
 	if (!new_pack) {
-		unlink(tmp_idx);
 		free(tmp_idx);
-
 		return -1; /* parse_pack_index() already issued error message */
 	}
 
 	ret = verify_pack_index(new_pack);
-	if (!ret)
-		close_pack_index(new_pack);
+
+	close_pack_index(new_pack);
 	free(tmp_idx);
-	if (ret)
+	if (ret) {
+		free(new_pack);
 		return -1;
+	}
 
 	packfile_list_prepend(packs, new_pack);
 	return 0;
-- 
2.54.0.129.g2dffd77b94.dirty