Fix an exception being thrown if a connection times out

Author: Kaliumhexacyanoferrat

Engine/Protocol/ClientHandler.cs

@@ -137,22 +137,13 @@ private async PooledValueTask<bool> HandleRequest(RequestBuilder builder, bool d
 
             KeepAlive ??= request["Connection"]?.Equals("Keep-Alive", StringComparison.InvariantCultureIgnoreCase) ?? true;
 
-            bool keepAlive = (bool)KeepAlive;
+            bool keepAlive = KeepAlive.Value;
 
             using var response = await Server.Handler.HandleAsync(request) ?? throw new InvalidOperationException("The root request handler did not return a response");
 
             var success = await ResponseHandler.Handle(request, response, keepAlive, dataRemaining);
 
-            if (!success || !keepAlive)
-            {
-                Connection.Shutdown(SocketShutdown.Both);
-                Connection.Disconnect(false);
-                Connection.Close();
-
-                return false;
-            }
-
-            return true;
+            return (success && keepAlive);
         }
 
         #endregion

Engine/Protocol/Parser/RequestParser.cs

@@ -45,7 +45,10 @@ internal RequestParser(NetworkConfiguration configuration)
 
         internal async PooledValueTask<RequestBuilder?> TryParseAsync(RequestBuffer buffer)
         {
-            await Type(buffer);
+            if (!await Type(buffer))
+            {
+                return null;
+            }
 
             await Path(buffer);
 
@@ -61,13 +64,18 @@ internal RequestParser(NetworkConfiguration configuration)
             return result;
         }
 
-        private async PooledValueTask Type(RequestBuffer buffer)
+        private async PooledValueTask<bool> Type(RequestBuffer buffer)
         {
             Scanner.Mode = ScannerMode.Words;
 
-            if (await Scanner.Next(buffer, RequestToken.Word))
+            if (await Scanner.Next(buffer, RequestToken.Word, allowNone: true))
             {
                 Request.Type(MethodConverter.ToRequestMethod(Scanner.Value));
+                return true;
+            }
+            else
+            {
+                return false;
             }
         }
 

Engine/Protocol/Parser/RequestScanner.cs

@@ -22,10 +22,15 @@ internal RequestScanner()
             Mode = ScannerMode.Words;
         }
 
-        internal async PooledValueTask<bool> Next(RequestBuffer buffer, RequestToken expectedToken)
+        internal async PooledValueTask<bool> Next(RequestBuffer buffer, RequestToken expectedToken, bool allowNone = false)
         {
             var read = await Next(buffer, forceRead: false);
 
+            if (allowNone && (read == RequestToken.None))
+            {
+                return false;
+            }
+
             if (read != expectedToken)
             {
                 throw new ProtocolException($"Unexpected token '{read}' (expected '{expectedToken}')");
@@ -54,7 +59,7 @@ internal async PooledValueTask<RequestToken> Next(RequestBuffer buffer, bool for
             }
             else
             {
-                throw new ProtocolException("No more data to be available to be parsed");
+                return Current = RequestToken.None;
             }
         }