Directory.EnumerateFiles fails to trim space on directory name, returns invalid file paths

[IanMercer]

Directory.Enumerate files concatenates the directory name and the found file name but does so without first trimming whitespace off the directory name. So instead of failing with an error or finding nothing it returns invalid file name strings like "C:\ \pagefile.sys" with a back slash, a space and another backslash.

I think the issue is here where it uses the original, untrimmed directory name.

    [Test]
    public void CanFindFilesWithSpaceOnEndOfDirectory()
    {
        string path = "C:\\ ";    // note: this has a space on the end of the path
        var pagefile = System.IO.Directory.EnumerateFiles(path, "pagefile.sys").First();
        pagefile.Should().Be("C:\\pagefile.sys");
    }

Results:

   Expected pagefile to be 
     "C:\pagefile.sys" with a length of 15, but 
     "C:\ \pagefile.sys" has a length of 17, differs near " \p" (index 3).

This is a .NETStandard 2.0 project building on VS 16.6.0 compiling to x64 but I don't think it's specific to that environment.

This test also fails, so maybe this needs fixing in Combine:

        string path = System.IO.Path.Combine("C:\\ ", "pagefile.sys");
        path.Should().Be("C:\\pagefile.sys");

[Clockwork-Muse]

It's possible to create directories with trailing whitespace (say, using WSL):

.... although Windows is not happy about it.

Linux, of course, works just fine with trailing whitespace.

[IanMercer]

@Clockwork-Muse Good point. My issue is the inconsistency in the Enumerate call: the search part succeeds because it trims the path, but the resulting filename fails because it doesn't.

Given that Linux allows directory names with a space on the end, the Enumerate call should probably fail to find C:\<space> rather than trimming it and returning bogus results. As coded, you could never Enumerate the files in a Linux directory with a space on the end of the directory name. Maybe that's the real bug here?

[Clockwork-Muse]

Probably.

[jozkee]

We probably want to investigate why the path in EnumerateFiles is being trimmed. If we decide to make the change we should consider that not trimming the whitespace on a next version could be considered breaking.