Protocol: [breaking] remove MessageBuffer.Dispose to avoid ownership …

…ambiguity. (#293)

src/Tmds.DBus.Protocol/MessageBuffer.cs

@@ -1,6 +1,6 @@
 namespace Tmds.DBus.Protocol;
 
-public sealed class MessageBuffer : IDisposable
+public sealed class MessageBuffer
 {
     private readonly MessageBufferPool _messagePool;
 
@@ -25,8 +25,10 @@ internal void Init(uint serial, MessageFlags flags, UnixFdCollection? handles)
         Handles = handles;
     }
 
-    public void Dispose() => ReturnToPool();
-
+    // Users should create a message using a MessageWriter
+    // and then hand it to the Connection class which is responsible for calling this method.
+    // A library user is never considered the owner of this message and therefore
+    // we don't provide a public method for a user to Dispose/ReturnToPool.
     internal void ReturnToPool()
     {
         _data.Reset();

src/Tmds.DBus.Protocol/MethodContext.cs

@@ -36,7 +36,7 @@ public void Reply(MessageBuffer message)
     {
         if (ReplySent || NoReplyExpected)
         {
-            message.Dispose();
+            message.ReturnToPool();
             if (ReplySent)
             {
                 throw new InvalidOperationException("A reply has already been sent.");