Moved NewLineFormat enum into its own source file

MimeKit/FormatOptions.cs

@@ -30,34 +30,6 @@
 using MimeKit.IO.Filters;
 
 namespace MimeKit {
-	/// <summary>
-	/// A New-Line format.
-	/// </summary>
-	/// <remarks>
-	/// There are two commonly used line-endings used by modern Operating Systems.
-	/// Unix-based systems such as Linux and macOS use a single character (<c>'\n'</c> aka LF)
-	/// to represent the end of line where-as Windows (or DOS) uses a sequence of two
-	/// characters (<c>"\r\n"</c> aka CRLF). Most text-based network protocols such as SMTP,
-	/// POP3, and IMAP use the CRLF sequence as well.
-	/// </remarks>
-	public enum NewLineFormat : byte {
-		/// <summary>
-		/// The Unix New-Line format (<c>"\n"</c>).
-		/// </summary>
-		Unix,
-
-		/// <summary>
-		/// The DOS New-Line format (<c>"\r\n"</c>).
-		/// </summary>
-		Dos,
-
-		/// <summary>
-		/// A mixed New-Line format where some lines use Unix-based line endings and
-		/// other lines use DOS-based line endings.
-		/// </summary>
-		Mixed,
-	}
-
 	/// <summary>
 	/// Format options for serializing various MimeKit objects.
 	/// </summary>

MimeKit/MimeMessage.cs

@@ -252,7 +252,7 @@ public MimeMessage (IEnumerable<Header> headers)
 			if (headers is HeaderList headerList) {
 				Headers = headerList;
 			} else {
-				Headers = new HeaderList (ParserOptions.Default);
+				Headers = new HeaderList (ParserOptions.Default.Clone ());
 
 				foreach (var header in headers)
 					Headers.Add (header);

MimeKit/NewLineFormat.cs

@@ -0,0 +1,55 @@
+//
+// NewLineFormat.cs
+//
+// Author: Jeffrey Stedfast <[email protected]>
+//
+// Copyright (c) 2013-2024 .NET Foundation and Contributors
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+
+namespace MimeKit {
+	/// <summary>
+	/// A New-Line format.
+	/// </summary>
+	/// <remarks>
+	/// There are two commonly used line-endings used by modern Operating Systems.
+	/// Unix-based systems such as Linux and macOS use a single character (<c>'\n'</c> aka LF)
+	/// to represent the end of line where-as Windows (or DOS) uses a sequence of two
+	/// characters (<c>"\r\n"</c> aka CRLF). Most text-based network protocols such as SMTP,
+	/// POP3, and IMAP use the CRLF sequence as well.
+	/// </remarks>
+	public enum NewLineFormat : byte {
+		/// <summary>
+		/// The Unix New-Line format (<c>"\n"</c>).
+		/// </summary>
+		Unix,
+
+		/// <summary>
+		/// The DOS New-Line format (<c>"\r\n"</c>).
+		/// </summary>
+		Dos,
+
+		/// <summary>
+		/// A mixed New-Line format where some lines use Unix-based line endings and
+		/// other lines use DOS-based line endings.
+		/// </summary>
+		Mixed,
+	}
+}