From 189349f42174cb812034eed11c3f51cdd379b9dd Mon Sep 17 00:00:00 2001
From: Tom Erez <etom@google.com>
Date: Fri, 16 Dec 2022 07:16:55 -0800
Subject: [PATCH] Don't add an empty "user" attribute to user sensors.

This fixes the broken TAP tests.

PiperOrigin-RevId: 495867491
Change-Id: I740651ed0dd8d1c84053a48f3fca577b6024bf95
---
 unity/Runtime/Components/Sensors/MjUserSensor.cs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/unity/Runtime/Components/Sensors/MjUserSensor.cs b/unity/Runtime/Components/Sensors/MjUserSensor.cs
index 2534e94a..51e7ec3b 100644
--- a/unity/Runtime/Components/Sensors/MjUserSensor.cs
+++ b/unity/Runtime/Components/Sensors/MjUserSensor.cs
@@ -32,8 +32,10 @@ public class MjUserSensor : MjBaseSensor {
     var mjcf = doc.CreateElement("user");
     mjcf.SetAttribute("name", Name);
     mjcf.SetAttribute("dim", $"{Dimension}");
-    // TODO: add validation that UserData is a space-separated list of floating numbers?
-    mjcf.SetAttribute("user", UserData);
+    if (!String.IsNullOrEmpty(UserData)) {
+      // TODO: add validation that UserData is a space-separated list of floating numbers?
+      mjcf.SetAttribute("user", UserData);
+    }
     return mjcf;
   }