From 4659d58066e51b47c568c9270a57368443dd13d0 Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Fri, 30 Aug 2024 16:53:00 +0100
Subject: [PATCH] [ros2controlcli] fix list_controllers when no controllers are
 loaded (#1721) (#1722)

---
 ros2controlcli/ros2controlcli/verb/list_controllers.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ros2controlcli/ros2controlcli/verb/list_controllers.py b/ros2controlcli/ros2controlcli/verb/list_controllers.py
index a26a1168a1..8367900cd5 100644
--- a/ros2controlcli/ros2controlcli/verb/list_controllers.py
+++ b/ros2controlcli/ros2controlcli/verb/list_controllers.py
@@ -99,6 +99,10 @@ def main(self, *, args):
         with NodeStrategy(args) as node:
             response = list_controllers(node, args.controller_manager)
 
+            if not response.controller:
+                print("No controllers are currently loaded!")
+                return 0
+
             # Structure data as table for nicer output
             col_width_name = max(len(ctrl.name) for ctrl in response.controller)
             col_width_type = max(len(ctrl.type) for ctrl in response.controller)