dir: If metadata is syntactically invalid, say which file is the problem

Similar to the previous commit, but for metadata.

Signed-off-by: Simon McVittie <[email protected]>

common/flatpak-dir.c

@@ -2983,7 +2983,7 @@ flatpak_dir_load_deployed (FlatpakDir *self,
 
  metakey = g_key_file_new ();
  if (!g_key_file_load_from_data (metakey, metadata_contents, metadata_size, 0, error))
- return NULL;
+ return glnx_prefix_error_null (error, "%s", flatpak_file_get_path_cached (metadata));
 
  deploy = flatpak_deploy_new (deploy_dir, ref, metakey, self->repo);
 
@@ -3633,7 +3633,7 @@ upgrade_deploy_data (GBytes *deploy_data,
  &metadata_contents, &metadata_size, NULL, error))
  return NULL;
  if (!g_key_file_load_from_data (keyfile, metadata_contents, metadata_size, 0, error))
- return NULL;
+ return glnx_prefix_error_null (error, "%s", flatpak_file_get_path_cached (metadata_file));
  add_metadata_to_deploy_data (&metadata_dict, keyfile);
 
  /* Add fields from appdata to deploy, since appdata-content-rating wasn't