fix #499

Author: b3b00

src/sly/lexer/GenericLexer.cs

@@ -1087,11 +1087,12 @@ public void AddSugarLexem(IN token, BuildResult<ILexer<IN>> buildResult, string
         }
 
         public void AddUpTo(IN token, BuildResult<ILexer<IN>> buildResult, string[] exceptions,
-            bool isLineEnding = false)
+            bool isLineEnding = false, int? channel = null)
         {
             NodeCallback<GenericToken> callback = match =>
             {
                 match.Properties[DerivedToken] = token;
+                match.Result.Channel = channel ?? Channels.Main;
                 return match;
             };
 

src/sly/lexer/LexerBuilder.cs

@@ -555,7 +555,7 @@ private static BuildResult<ILexer<IN>> BuildGenericLexer<IN>(IDictionary<IN, Lis
 
                         if (lexeme.IsUpTo)
                         {
-                            lexer.AddUpTo(tokenID, result, lexeme.GenericTokenParameters);
+                            lexer.AddUpTo(tokenID, result, lexeme.GenericTokenParameters, channel:lexeme.Channel);
                         }
 
                         if (lexeme.IsString)

tests/ParserTests/Issue499/Issue499Test.cs

@@ -19,6 +19,8 @@ public void LexemeChannelNullable_Test()
         var lexResult = lexer.Tokenize("test\"");
         Check.That(lexResult).IsOkLexing();
         var tokenChannels = lexResult.Tokens;
-        Check.That(tokenChannels.GetChannel(1).Count).IsGreaterOrEqualThan(1);
+        Check.That(tokenChannels).CountIs(2);
+        Check.That(tokenChannels.GetChannel(1).Tokens).CountIs(1);
+        Check.That(tokenChannels.GetChannel(1).Tokens[0].TokenID).IsEqualTo(Issue499Token.Test);
     }
 }