Merge branch 'kl/cat-file-on-sparse-index'

"git cat-file" works well with the sparse-index, and gets marked as
such.

* kl/cat-file-on-sparse-index:
  builtin/cat-file: mark 'git cat-file' sparse-index compatible
  t1092: allow run_on_* functions to use standard input

builtin/cat-file.c

@@ -1047,6 +1047,9 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
 	if (batch.buffer_output < 0)
 		batch.buffer_output = batch.all_objects;
 
+	prepare_repo_settings(the_repository);
+	the_repository->settings.command_requires_full_index = 0;
+
 	/* Return early if we're in batch mode? */
 	if (batch.enabled) {
 		if (opt_cw)