IOException when ParserSettings loaded in WPF App

[LordPinhead]

When i use the Library in my WPF App (not Console App), there will be thrown an IOException in the Constructor of ParserSettings. It will be catched and DefaultMaximumHeight will be set.
But it would, in my opinion, cleaner with that code:

            try
            {
                if (Console.IsOutputRedirected || Console.WindowWidth < 1)
                {
                    maximumDisplayWidth = DefaultMaximumLength;
                }
                else
                {
                    maximumDisplayWidth = Console.WindowWidth;
                }
            }
            catch (IOException)
            {
                maximumDisplayWidth = DefaultMaximumLength;
            }

If you agree, i could do a pull request and merge it.

Best regards
Lord_Pinhead

[jairbubbles]

Same problem here.

Your solution seems good to me!

[moh-hassan]

@LordPinhead
Is the issue still exist in v2.5.0?

[JakubLinhart]

Same issue in 2.5.0:

 	mscorlib.dll!System.IO.__Error.WinIOError(int errorCode, string maybeFullPath)	Unknown
 	mscorlib.dll!System.Console.GetBufferInfo(bool throwOnNoConsole, out bool succeeded)	Unknown
 	mscorlib.dll!System.Console.WindowWidth.get()	Unknown
 	CommandLine.dll!CommandLine.ParserSettings.ParserSettings()	Unknown
 	CommandLine.dll!CommandLine.Parser..cctor.AnonymousMethod__20_0()	Unknown
 	mscorlib.dll!System.Lazy<CommandLine.Parser>.CreateValue()	Unknown
 	mscorlib.dll!System.Lazy<CommandLine.Parser>.LazyInitValue()	Unknown

[moh-hassan]

Can you post a simple demo application to repro your issue.

[moh-hassan]

I couldn't repro your issue , and my wpf demo application is working fine.
Have a look to the attached project and modify it to reproduce the Exception, or send me you demo for investigation.

WpfApp1.zip

[JakubLinhart]

I'm not able to reproduce it in a minimal example project. It works fine for me also. The real project is far from "minimal": https://github.com/uoinfusion/Infusion/blob/e88086438a78eb7d388b5122e9ceb9cc535210fe/Infusion.Desktop/CommandLine/Handler.cs#L15

[LordPinhead]

When i am back at work, i will make a sample projekt, should be online by the end of the week.

[LordPinhead]

You Need to deactivate "Options -> Debugging -> Just my code" or the Exception will never be printed in Visual Studio. The Exception will still occure, but hidden.
I send the Project home to upload it, our Firewall dont like Github Uploads :-)

[moh-hassan]

I tried the next unit test for range of values 0-20 of MaximumDisplayWidth

    [Fact]
    public void Test1()
    {            
        var setting= new ParserSettings
        {
            MaximumDisplayWidth = 1, //cause error in range 1-20 , and may be different range based on the length of specification
            HelpWriter = Console.Out
        };
        var args=new string[] {"zz"};
        var parser= new Parser(setting);
        var result= parser.ParseArguments<Simple_Options>(args);
       
    }

An Exception is fired:

System.ArgumentOutOfRangeException
Length cannot be less than zero.
Parameter name: length
at System.String.Substring(Int32 startIndex, Int32 length)
at CommandLine.Text.HelpText.AddOption(String requiredWord, Int32 maxLength, Specification specification, Int32 widthOfHelpText) in F:\commandline-2.5\CommandlineFork_2.5\src\CommandLine\Text\HelpText.cs:line 846
...

The following line is the start of the cause of error

      // L#781 in HelpText.cs
     // private HelpText AddOptionsImpl(IEnumerable<Specification> specifications, string requiredWord, int maximumLength)		

     var remainingSpace = maximumLength - (maxLength + 6);

The remainingSpace is negative and cause string processing error

I think this module of wrapping lines need heavily debugging and correction to avoid the negative value
and DisplayWidth should have also minimum value to be adjusted

This revision and correction need co-operation with us to resolve this issue and submit PR.

[moh-hassan]

@LordPinhead
Waiting your Repro demo :)

[LordPinhead]

Sorry, had a little stress the last week. Have a look https://github.com/LordPinhead/CommandLineWPFTestApp , just deactivate the "debug own code only" option.

[moh-hassan]

Thanks @LordPinhead for the Demo.
I could repro the IOException using your demo.
The root problem is the Redirection of Console, so this line raise the IOException:

              maximumDisplayWidth = Console.WindowWidth;

The limits in using your solution Is that Console.IsOutputRedirected isn't supported in net40 and the Compiler raise the error:

Error CS0117 'Console' does not contain a definition for 'IsOutputRedirected'

Also, Console.WindowWidth can cause other Exceptions like ArgumentOutOfRangeException

The try ..catch clause stop the propagation of IOException, catch it and handling it:

           try
           {
          ...
           catch (IOException)
          {
           maximumDisplayWidth = DefaultMaximumLength;
          }

What is you suggestion?

[LordPinhead]

If Console.IsOutputRedirected is 4.5 and up, we could use preprocessor ifs.

´´´
#if NET40
// Do something, i could look it up like using System.Console.WindowHeight
#else
// Console.IsOutputRedirected Fix

´´´

So we could route depending on the framework used

[jairbubbles]

I think you can just remove the test on NET40.

Most WPF app nowadays will target NET45. The goal here is just to suppress an exception. I doubt we can achhieve it without that function.

[LordPinhead]

Whats the status? Should it be cut off from Net40 or not? At some point, there will be no systems using the old framework and i think it's time to send Net40 into his retirement.

[dos-ise]

I can still reproduce this with version 2.7.82
Are there any updates?

[moh-hassan]

The exception is handled by try ..catch and is not fired at Release Configuration. It's caught and swallowed by setting Console.WindowWidth=80 when redirected in WPF.
In debugging, you can configure the debugger to ignore breaking on the First Chance Exception of IOException and it will ignore it (because it's handled and not re-thrown again) using Debug > Windows > Exception Settings.

This issue will be fixed in the next release.