From ef2dec992c9f9aac189b176c1c61abc8624b28be Mon Sep 17 00:00:00 2001
From: sta <sta.blockhead@gmail.com>
Date: Sun, 9 Jun 2019 22:34:21 +0900
Subject: [PATCH] [Modify] Throw exception

---
 websocket-sharp/Ext.cs | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/websocket-sharp/Ext.cs b/websocket-sharp/Ext.cs
index a8767674..72b88599 100644
--- a/websocket-sharp/Ext.cs
+++ b/websocket-sharp/Ext.cs
@@ -1584,15 +1584,25 @@ namespace WebSocketSharp
     /// </typeparam>
     public static T[] SubArray<T> (this T[] array, int startIndex, int length)
     {
-      int len;
-      if (array == null || (len = array.Length) == 0)
-        return new T[0];
+      if (array == null)
+        throw new ArgumentNullException ("array");
 
-      if (startIndex < 0 || length <= 0 || startIndex + length > len)
-        return new T[0];
+      var len = array.Length;
+      if (len == 0) {
+        if (startIndex != 0)
+          throw new ArgumentOutOfRangeException ("startIndex");
+
+        if (length != 0)
+          throw new ArgumentOutOfRangeException ("length");
 
-      if (startIndex == 0 && length == len)
         return array;
+      }
+
+      if (startIndex < 0 || startIndex > len - 1)
+        throw new ArgumentOutOfRangeException ("startIndex");
+
+      if (length < 0 || length > len - startIndex)
+        throw new ArgumentOutOfRangeException ("length");
 
       var subArray = new T[length];
       Array.Copy (array, startIndex, subArray, 0, length);