1 files changed, 34 insertions, 26 deletions
diff --git a/src/mscorlib/src/System/Text/Encoding.cs b/src/mscorlib/src/System/Text/Encoding.cs
index ee4b7ec64c..8cb01e41fa 100644
--- a/src/mscorlib/src/System/Text/Encoding.cs
+++ b/src/mscorlib/src/System/Text/Encoding.cs
@@ -745,14 +745,20 @@ namespace System.Text
         [Pure]
         public int GetByteCount(string s, int index, int count)
         {
-            if ((s == null) ||
-                (index < 0) ||
-                (count < 0) ||
-                (index > s.Length - count))
-            {
-                EncodingForwarder.ThrowValidationFailed(s, index, count);
-            }
+            if (s == null)
+                throw new ArgumentNullException(nameof(s), 
+                    Environment.GetResourceString("ArgumentNull_String"));
+            if (index < 0)
+                throw new ArgumentOutOfRangeException(nameof(index),
+                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
+            if (count < 0)
+                throw new ArgumentOutOfRangeException(nameof(count),
+                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
+            if (index > s.Length - count)
+                throw new ArgumentOutOfRangeException(nameof(index),
+                      Environment.GetResourceString("ArgumentOutOfRange_IndexCount"));
             Contract.EndContractBlock();
+
             unsafe
             {
                 fixed (char* pChar = s)
@@ -859,37 +865,39 @@ namespace System.Text
         // string range.
         //
         [Pure]
-        public unsafe byte[] GetBytes(string s, int index, int count)
+        public byte[] GetBytes(string s, int index, int count)
         {
-            if ((s == null) ||
-                (index < 0) ||
-                (count < 0) ||
-                (index > s.Length - count))
-            {
-                EncodingForwarder.ThrowValidationFailed(s, index, count);
-            }
+            if (s == null)
+                throw new ArgumentNullException(nameof(s),
+                    Environment.GetResourceString("ArgumentNull_String"));
+            if (index < 0)
+                throw new ArgumentOutOfRangeException(nameof(index),
+                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
+            if (count < 0)
+                throw new ArgumentOutOfRangeException(nameof(count),
+                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
+            if (index > s.Length - count)
+                throw new ArgumentOutOfRangeException(nameof(index),
+                      Environment.GetResourceString("ArgumentOutOfRange_IndexCount"));
             Contract.EndContractBlock();
 
-            byte[] bytes;
-            fixed (char* pChar = s)
+            unsafe
             {
-                int byteCount = GetByteCount(pChar + index, count);
-                if (byteCount == 0)
-                {
-                    bytes = Array.Empty<byte>();
-                }
-                else
+                fixed (char* pChar = s)
                 {
-                    bytes = new byte[byteCount];
+                    int byteCount = GetByteCount(pChar + index, count);
+                    if (byteCount == 0)
+                        return Array.Empty<byte>();
+
+                    byte[] bytes = new byte[byteCount];
                     fixed (byte* pBytes = &bytes[0])
                     {
                         int bytesReceived = GetBytes(pChar + index, count, pBytes, byteCount);
                         Debug.Assert(byteCount == bytesReceived);
                     }
+                    return bytes;
                 }
             }
-            
-            return bytes;
         }
 
         public virtual int GetBytes(String s, int charIndex, int charCount,