object-file: fix memory leak in `force_object_loose()`

We return an error when converting the given object to the compatibility
hash algorithm fails. This early return causes a memory leak though,
because we don't free the content buffer that we've already read before
via `odb_read_object_info_extended()`.

Plug the memory leak by creating a common exit path where the buffer
gets free'd.

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

diff --git a/object-file.c b/object-file.c
index 5b075309506334389cf63e4725ed68d8011bfe86..067a63a4f1e13b949465f3a8e04b39c9e3979018 100644 (file)
--- a/object-file.c
+++ b/object-file.c
@@ -898,7 +898,7 @@ int force_object_loose(struct odb_source *source,
 {
        struct odb_source_files *files = odb_source_files_downcast(source);
        const struct git_hash_algo *compat = source->odb->repo->compat_hash_algo;
-       void *buf;
+       void *buf = NULL;
        size_t len;
        struct object_info oi = OBJECT_INFO_INIT;
        struct object_id compat_oid;
@@ -916,19 +916,29 @@ int force_object_loose(struct odb_source *source,
        oi.typep = &type;
        oi.sizep = &len;
        oi.contentp = &buf;
-       if (odb_read_object_info_extended(source->odb, oid, &oi, 0))
-               return error(_("cannot read object for %s"), oid_to_hex(oid));
+       if (odb_read_object_info_extended(source->odb, oid, &oi, 0)) {
+               ret = error(_("cannot read object for %s"), oid_to_hex(oid));
+               goto out;
+       }
+
        if (compat) {
-               if (repo_oid_to_algop(source->odb->repo, oid, compat, &compat_oid))
-                       return error(_("cannot map object %s to %s"),
-                                    oid_to_hex(oid), compat->name);
+               if (repo_oid_to_algop(source->odb->repo, oid, compat, &compat_oid)) {
+                       ret = error(_("cannot map object %s to %s"),
+                                   oid_to_hex(oid), compat->name);
+                       goto out;
+               }
        }
+
        hdrlen = format_object_header(hdr, sizeof(hdr), type, len);
        ret = write_loose_object(files->loose, oid, hdr, hdrlen, buf, len, mtime, 0);
-       if (!ret && compat)
+       if (ret)
+               goto out;
+
+       if (compat)
                ret = repo_add_loose_object_map(files->loose, oid, &compat_oid);
-       free(buf);
 
+out:
+       free(buf);
        return ret;
 }