Conditions followed by single EOL failed to be processed

[vlada-shubina]

Examples:

            string value = @"Hello
#if (1.2 > 2.5)
#endif
";
            string expected = @"Hello
";

            byte[] valueBytes = Encoding.UTF8.GetBytes(value);
            MemoryStream input = new MemoryStream(valueBytes);
            MemoryStream output = new MemoryStream();

            VariableCollection vc = new VariableCollection();
            IProcessor processor = SetupCStyleNoCommentsProcessor(vc);

            //Changes should be made
            bool changed = processor.Run(input, output, 50);
            Verify(Encoding.UTF8, output, changed, value, expected);

    Expected: Hello\r\n
    Actual:   Hello\r\n#endif\r\n

            string value = @"Hello
<!--#if (B)
bar
#endif -->
";
            string expected = @"Hello
";

            byte[] valueBytes = Encoding.UTF8.GetBytes(value);
            MemoryStream input = new MemoryStream(valueBytes);
            MemoryStream output = new MemoryStream();

            VariableCollection vc = new VariableCollection();
            IProcessor processor = SetupXmlStyleProcessor(vc);

            //Changes should be made
            bool changed = processor.Run(input, output, 50);
            Verify(Encoding.UTF8, output, changed, value, expected);;

    Expected: Hello\r\n
    Actual:   Hello\r\n#endif -->\r\n

Some notes:
The case happens when condition is false and ends with empty line.
Then in ProcessorState.Run during HandleMatch for condition the buffer is moved to the end, however not OldestRequiredSequenceNumber for TrieEvaluation.
Due to this, buffer advancing logic proceeds only toOldestRequiredSequenceNumber with offset which is after if condition.
The endif is getting processed once again as unbalanced condition and gets output.

The fix is potentially "accepting" or "finalizes matches" after HandleMatch is done, so last known sequence number is updated and double processing does not happen. Then buffer will be updated to the end and processing stops. After "false" condition branch anyway doesn't make sense to process the open tries. As section is skipped, they won't be matched.

[DamianEdwards]

I think I'm hitting this issue at the moment building a new project template in ASP.NET Core 8. The Program.cs file has a conditional block at the end of the file and if the condition is false, I end up with a trailing #endif in the output. If I remove the #endif from the template, both conditions "work" but in the false case there are no blank lines at the end of the file. No matter what combination I try I can't get the false case to result in a single blank line at the end of the file (as per our usual standard).

[aivanov-oneinc]

Having it too with the YAML file. dotnet sdk 7.
Workaround it with adding 2 blank lines at the end of file.