Use EncodingForwarder for GetByteCount(char[], int, int)

src/mscorlib/mscorlib.shared.sources.props

@@ -982,6 +982,7 @@
     <TextSources Include="$(BclSourcesRoot)\System\Text\EncoderFallback.cs" />
     <TextSources Include="$(BclSourcesRoot)\System\Text\EncoderReplacementFallback.cs" />
     <TextSources Include="$(BclSourcesRoot)\System\Text\Encoding.cs" />
+    <TextSources Include="$(BclSourcesRoot)\System\Text\EncodingForwarder.cs" />
     <TextSources Include="$(BclSourcesRoot)\System\Text\EncodingInfo.cs" />
     <TextSources Include="$(BclSourcesRoot)\System\Text\EncodingNLS.cs" />
     <TextSources Include="$(BclSourcesRoot)\System\Text\EncodingProvider.cs" />

src/mscorlib/src/System/Text/ASCIIEncoding.cs

@@ -56,29 +56,9 @@ internal override void SetDefaultFallbacks()
         // parent method is safe
 
         [System.Security.SecuritySafeCritical]  // auto-generated
-        public override unsafe int GetByteCount(char[] chars, int index, int count)
+        public override int GetByteCount(char[] chars, int index, int count)
         {
-            // Validate input parameters
-            if (chars == null)
-                throw new ArgumentNullException("chars",
-                      Environment.GetResourceString("ArgumentNull_Array"));
-
-            if (index < 0 || count < 0)
-                throw new ArgumentOutOfRangeException((index<0 ? "index" : "count"),
-                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
-
-            if (chars.Length - index < count)
-                throw new ArgumentOutOfRangeException("chars",
-                      Environment.GetResourceString("ArgumentOutOfRange_IndexCountBuffer"));
-            Contract.EndContractBlock();
-
-            // If no input, return 0, avoid fixed empty array problem
-            if (count == 0)
-                return 0;
-
-            // Just call the pointer version
-            fixed (char* pChars = chars)
-                return GetByteCount(pChars + index, count, null);
+            return EncodingForwarder.GetByteCount(this, chars, index, count);
         }
 
         // All of our public Encodings that don't use EncodingNLS must have this (including EncodingNLS)

src/mscorlib/src/System/Text/EncodingForwarder.cs

@@ -0,0 +1,53 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics.Contracts;
+
+namespace System.Text
+{
+    // Shared implementations for commonly overriden Encoding methods
+
+    internal static class EncodingForwarder
+    {
+        // We normally have to duplicate a lot of code between UTF8Encoding,
+        // UTF7Encoding, EncodingNLS, etc. because we want to override many
+        // of the methods in all of those classes to just forward to the unsafe
+        // version. (e.g. GetBytes(char[]))
+        // Ideally, everything would just derive from EncodingNLS, but that's
+        // not exposed in the public API, and C# prohibits a public class from
+        // inheriting from an internal one. So, we have to override each of the
+        // methods in question and repeat the argument validation/logic.
+
+        // These set of methods exist so instead of duplicating code, we can
+        // simply have those overriden methods call here to do the actual work.
+
+        public unsafe static int GetByteCount(Encoding encoding, char[] chars, int index, int count)
+        {
+            // Validate parameters
+
+            Contract.Assert(encoding != null); // this parameter should only be affected internally, so just do a debug check here
+            if (chars == null)
+            {
+                throw new ArgumentNullException("chars", Environment.GetResourceString("ArgumentNull_Array"));
+            }
+            if (index < 0 || count < 0)
+            {
+                throw new ArgumentOutOfRangeException(index < 0 ? "index" : "count", Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
+            }
+            if (chars.Length - index < count)
+            {
+                throw new ArgumentOutOfRangeException("chars", Environment.GetResourceString("ArgumentOutOfRange_IndexCountBuffer"));
+            }
+            Contract.EndContractBlock();
+
+            // If no input, return 0, avoid fixed empty array problem
+            if (count == 0)
+                return 0;
+
+            // Just call the pointer version
+            fixed (char* pChars = chars)
+                return encoding.GetByteCount(pChars + index, count, null);
+        }
+    }
+}

src/mscorlib/src/System/Text/EncodingNLS.cs

@@ -42,29 +42,9 @@ protected EncodingNLS(int codePage) : base(codePage)
         // EncodingNLS, UTF7Encoding, UTF8Encoding, UTF32Encoding, ASCIIEncoding, UnicodeEncoding
         // parent method is safe
         [System.Security.SecuritySafeCritical] // overrides public transparent member
-        public override unsafe int GetByteCount(char[] chars, int index, int count)
+        public override int GetByteCount(char[] chars, int index, int count)
         {
-            // Validate input parameters
-            if (chars == null)
-                throw new ArgumentNullException("chars", 
-                      Environment.GetResourceString("ArgumentNull_Array"));
-
-            if (index < 0 || count < 0)
-                throw new ArgumentOutOfRangeException((index<0 ? "index" : "count"), 
-                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
-
-            if (chars.Length - index < count)
-                throw new ArgumentOutOfRangeException("chars",
-                      Environment.GetResourceString("ArgumentOutOfRange_IndexCountBuffer"));
-            Contract.EndContractBlock();
-
-            // If no input, return 0, avoid fixed empty array problem
-            if (count == 0)
-                return 0;
-
-            // Just call the pointer version
-            fixed (char* pChars = chars)
-                return GetByteCount(pChars + index, count, null);
+            return EncodingForwarder.GetByteCount(this, chars, index, count);
         }
 
         // All of our public Encodings that don't use EncodingNLS must have this (including EncodingNLS)

src/mscorlib/src/System/Text/UTF32Encoding.cs

@@ -95,29 +95,9 @@ internal override void SetDefaultFallbacks()
         // parent method is safe
 
         [System.Security.SecuritySafeCritical]  // auto-generated
-        public override unsafe int GetByteCount(char[] chars, int index, int count)
+        public override int GetByteCount(char[] chars, int index, int count)
         {
-            // Validate input parameters
-            if (chars == null)
-                throw new ArgumentNullException("chars",
-                      Environment.GetResourceString("ArgumentNull_Array"));
-
-            if (index < 0 || count < 0)
-                throw new ArgumentOutOfRangeException((index<0 ? "index" : "count"),
-                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
-
-            if (chars.Length - index < count)
-                throw new ArgumentOutOfRangeException("chars",
-                      Environment.GetResourceString("ArgumentOutOfRange_IndexCountBuffer"));
-            Contract.EndContractBlock();
-
-            // If no input, return 0, avoid fixed empty array problem
-            if (count == 0)
-                return 0;
-
-            // Just call the pointer version
-            fixed (char* pChars = chars)
-                return GetByteCount(pChars + index, count, null);
+            return EncodingForwarder.GetByteCount(this, chars, index, count);
         }
 
         // All of our public Encodings that don't use EncodingNLS must have this (including EncodingNLS)

src/mscorlib/src/System/Text/UTF7Encoding.cs

@@ -161,29 +161,9 @@ public override int GetHashCode()
         // parent method is safe
 
         [System.Security.SecuritySafeCritical]  // auto-generated
-        public override unsafe int GetByteCount(char[] chars, int index, int count)
+        public override int GetByteCount(char[] chars, int index, int count)
         {
-            // Validate input parameters
-            if (chars == null)
-                throw new ArgumentNullException("chars",
-                      Environment.GetResourceString("ArgumentNull_Array"));
-
-            if (index < 0 || count < 0)
-                throw new ArgumentOutOfRangeException((index<0 ? "index" : "count"),
-                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
-
-            if (chars.Length - index < count)
-                throw new ArgumentOutOfRangeException("chars",
-                      Environment.GetResourceString("ArgumentOutOfRange_IndexCountBuffer"));
-            Contract.EndContractBlock();
-
-            // If no input, return 0, avoid fixed empty array problem
-            if (count == 0)
-                return 0;
-
-            // Just call the pointer version
-            fixed (char* pChars = chars)
-                return GetByteCount(pChars + index, count, null);
+            return EncodingForwarder.GetByteCount(this, chars, index, count);
         }
 
         // All of our public Encodings that don't use EncodingNLS must have this (including EncodingNLS)

src/mscorlib/src/System/Text/UTF8Encoding.cs

@@ -119,29 +119,9 @@ internal override void SetDefaultFallbacks()
         // parent method is safe
 
         [System.Security.SecuritySafeCritical]  // auto-generated
-        public override unsafe int GetByteCount(char[] chars, int index, int count)
+        public override int GetByteCount(char[] chars, int index, int count)
         {
-            // Validate input parameters
-            if (chars == null)
-                throw new ArgumentNullException("chars",
-                      Environment.GetResourceString("ArgumentNull_Array"));
-
-            if (index < 0 || count < 0)
-                throw new ArgumentOutOfRangeException((index<0 ? "index" : "count"),
-                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
-
-            if (chars.Length - index < count)
-                throw new ArgumentOutOfRangeException("chars",
-                      Environment.GetResourceString("ArgumentOutOfRange_IndexCountBuffer"));
-            Contract.EndContractBlock();
-
-            // If no input, return 0, avoid fixed empty array problem
-            if (count == 0)
-                return 0;
-
-            // Just call the pointer version
-            fixed (char* pChars = chars)
-                return GetByteCount(pChars + index, count, null);
+            return EncodingForwarder.GetByteCount(this, chars, index, count);
         }
 
         // All of our public Encodings that don't use EncodingNLS must have this (including EncodingNLS)

src/mscorlib/src/System/Text/UnicodeEncoding.cs

@@ -93,29 +93,9 @@ internal override void SetDefaultFallbacks()
         // parent method is safe
 
         [System.Security.SecuritySafeCritical]  // auto-generated
-        public override unsafe int GetByteCount(char[] chars, int index, int count)
+        public override int GetByteCount(char[] chars, int index, int count)
         {
-            // Validate input parameters
-            if (chars == null)
-                throw new ArgumentNullException("chars",
-                      Environment.GetResourceString("ArgumentNull_Array"));
-
-            if (index < 0 || count < 0)
-                throw new ArgumentOutOfRangeException((index<0 ? "index" : "count"),
-                      Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
-
-            if (chars.Length - index < count)
-                throw new ArgumentOutOfRangeException("chars",
-                      Environment.GetResourceString("ArgumentOutOfRange_IndexCountBuffer"));
-            Contract.EndContractBlock();
-
-            // If no input, return 0, avoid fixed empty array problem
-            if (count == 0)
-                return 0;
-
-            // Just call the pointer version
-            fixed (char* pChars = chars)
-                return GetByteCount(pChars + index, count, null);
+            return EncodingForwarder.GetByteCount(this, chars, index, count);
         }
 
         // All of our public Encodings that don't use EncodingNLS must have this (including EncodingNLS)