From 63ed9eaaa6bba3061b0d658235337a56525e0506 Mon Sep 17 00:00:00 2001
From: "Addisu Z. Taddese" <addisu@openrobotics.org>
Date: Thu, 21 Sep 2023 12:13:01 -0500
Subject: [PATCH] Fix crash when starting Topic Viewer (#574)

Signed-off-by: Addisu Z. Taddese <addisu@openrobotics.org>
---
 src/plugins/topic_viewer/TopicViewer.cc | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/plugins/topic_viewer/TopicViewer.cc b/src/plugins/topic_viewer/TopicViewer.cc
index 7e95a79c1..9fce9866a 100644
--- a/src/plugins/topic_viewer/TopicViewer.cc
+++ b/src/plugins/topic_viewer/TopicViewer.cc
@@ -202,8 +202,11 @@ void TopicViewerPrivate::CreateModel()
     std::vector<transport::MessagePublisher> publishers;
     std::vector<transport::MessagePublisher> subscribers;
     this->node.TopicInfo(topics[i], publishers, subscribers);
-    std::string msgType = publishers[0].MsgTypeName();
-    this->AddTopic(topics[i], msgType);
+    if (!publishers.empty())
+    {
+      std::string msgType = publishers[0].MsgTypeName();
+      this->AddTopic(topics[i], msgType);
+    }
   }
 }