builtin rebase: actions require a rebase in progress

This commit prevents actions (such as --continue, --skip) from running
when there is no rebase in progress.

Signed-off-by: Pratik Karki <predatoramigo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/rebase.c

@@ -577,6 +577,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		usage_with_options(builtin_rebase_usage,
 				   builtin_rebase_options);
 
+	if (action != NO_ACTION && !in_progress)
+		die(_("No rebase in progress?"));
+
 	if (action == ACTION_EDIT_TODO && !is_interactive(&options))
 		die(_("The --edit-todo action can only be used during "
 		      "interactive rebase."));