Documentation: Handling of problematic paths on Windows

[jkotas]

Context: #120639 (comment)

The documentation for handling of problematic paths on Windows, such as paths that with trailing spaces, needs improvements.

• There is https://learn.microsoft.com/en-us/dotnet/framework/migration-guide/mitigation-path-normalization however it talks about .NET Framework and it is not clear which parts of it apply to .NET Core

• The documentation for various System.IO APIs include snippets that are either applicable to Windows only or .NET Framework only. For example, https://learn.microsoft.com/en-us/dotnet/api/system.io.directory.createdirectory says "Trailing spaces are removed from the end of the path parameter before creating the directory." that is applicable to Windows only.

• The documentation should include best practices for writing code that handles these paths correctly.

  • FileInfo and DirectoryInfo do support the trailing spaces, File and Directory do not.
    • Handles these paths correctly: foreach (var ff in new DirectoryInfo(".").EnumerateFiles()) { using (var fs = fi..Open(FileMode.Open)) { ... } }
    • This is going to fail on these paths: foreach (var f in Directory.EnumerateFiles(".")) { using (var fs = File.Open(f, FileMode.Open)) { ... } }

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[vladd]

I would say it’s quite confusing that some APIs support trailing spaces and some don’t support. Why not just make the APIs consistent?