From a6c6607368d8012814df6cece0749f6a078894c3 Mon Sep 17 00:00:00 2001
From: Dean Ferreyra <dean.ferreyra@oneilsoft.com>
Date: Thu, 30 Sep 2021 16:07:58 -0700
Subject: [PATCH] Change the utf-8 encoding to elide the BOM

The "main_encoding" encoding is used for creating file lists.  Without this change, if "main_encoding" is set to "utf-8", file lists that are written include the UTF-8 BOM which causes errors in Mercurial.
---
 src/Mercurial.Net/ClientExecutable.cs | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/Mercurial.Net/ClientExecutable.cs b/src/Mercurial.Net/ClientExecutable.cs
index 7e11ca0..45936a8 100644
--- a/src/Mercurial.Net/ClientExecutable.cs
+++ b/src/Mercurial.Net/ClientExecutable.cs
@@ -325,7 +325,7 @@ public static Encoding GetMainEncoding()
 
             try
             {
-                return Encoding.GetEncoding(encName);
+                return GetEncoding(encName);
             }
             catch
             {
@@ -347,7 +347,7 @@ public static Encoding GetTerminalEncoding()
 
             try
             {
-                return Encoding.GetEncoding(encName);
+                return GetEncoding(encName);
             }
             catch
             {
@@ -356,6 +356,28 @@ public static Encoding GetTerminalEncoding()
 
         }
 
+        /// <summary>
+        /// Returns an encoding based on the name.  Specifically for the
+        /// case of "utf-8", it returns a UTF-8 encoding without the BOM.
+        /// </summary>
+        private static Encoding GetEncoding(string encName)
+        {
+            // By retrieving the requested encoding first we can compare
+            // against the well-defined web name "utf-8" and not worry
+            // about how the encoding providers resolved the string in
+            // encName.
+            var encoding = Encoding.GetEncoding(encName);
+            if (encoding.WebName == "utf-8")
+            {
+                // Return UTF-8 encoding without the BOM.
+                return new UTF8Encoding(false, true);
+            }
+            else
+            {
+                return encoding;
+            }
+        }
+
         /// <summary>
         /// Attempts to locate the command line client executable.
         /// </summary>