From 700f47b42a99ddfd9829d9c843fe8f546adb3968 Mon Sep 17 00:00:00 2001
From: Masataka SUMI <santarh@gmail.com>
Date: Fri, 2 Jul 2021 15:37:34 +0900
Subject: [PATCH] Add null check

---
 Assets/UniGLTF/Runtime/Extensions/StringExtensions.cs | 10 ++++++++++
 Assets/UniGLTF/Runtime/UniGLTF/Format/glTFTexture.cs  |  2 +-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/Assets/UniGLTF/Runtime/Extensions/StringExtensions.cs b/Assets/UniGLTF/Runtime/Extensions/StringExtensions.cs
index 62e3b7170..635e1e0d2 100644
--- a/Assets/UniGLTF/Runtime/Extensions/StringExtensions.cs
+++ b/Assets/UniGLTF/Runtime/Extensions/StringExtensions.cs
@@ -76,6 +76,11 @@ namespace UniGLTF
         // https://docs.unity3d.com/Manual/BestPracticeUnderstandingPerformanceInUnity5.html
         public static bool FastStartsWith(this string a, string b)
         {
+            if (a == null || b == null)
+            {
+                return false;
+            }
+
             var aLen = a.Length;
             var bLen = b.Length;
             if (aLen < bLen)
@@ -94,6 +99,11 @@ namespace UniGLTF
 
         public static bool FastEndsWith(this string a, string b)
         {
+            if (a == null || b == null)
+            {
+                return false;
+            }
+
             var aLen = a.Length;
             var bLen = b.Length;
             if (aLen < bLen)
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/Format/glTFTexture.cs b/Assets/UniGLTF/Runtime/UniGLTF/Format/glTFTexture.cs
index b04b2549c..6ec8065e7 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/Format/glTFTexture.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/Format/glTFTexture.cs
@@ -68,7 +68,7 @@ namespace UniGLTF
                     }
                     else
                     {
-                        return Path.GetExtension(uri).ToLower();
+                        return Path.GetExtension(uri)?.ToLowerInvariant() ?? string.Empty;
                     }
             }
         }