(Error .Net Core 5) "Directory.GetDirectories("D:")" returns not existingDirectory

[vsfeedback]

This issue has been moved from a ticket on Developer Community.

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String[] dirSSS = Directory.GetDirectories("D:");
dirSSS[0];             // Output:  "D:\ref" (without quotes) <-- no this directory on disk "D:"!
Environment.Version;   // "5.0.13" (Net Core)
Environment.OSVersion; // "Microsoft Windows NT 6.3.9600.0"
                       // VS (Russian):
                       //    Microsoft Visual Studio Professional&nbsp;2019
                       //    Версия 16.11.9

There is another theme with this error, but it closed:
https://developercommunity2.visualstudio.com/t/DirectoryGetDirectoriesdrive-return-a/175411?entry=suggestion&space=8&preview2=true

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Original Comments

Feedback Bot on 3/21/2022, 00:32 AM:

(private comment, text removed)

[ghost]

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See info in area-owners.md if you want to be subscribed.

Issue Details

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This issue has been moved from a ticket on Developer Community.

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String[] dirSSS = Directory.GetDirectories("D:");
dirSSS[0];             // Output:  "D:\ref" (without quotes) <-- no this directory on disk "D:"!
Environment.Version;   // "5.0.13" (Net Core)
Environment.OSVersion; // "Microsoft Windows NT 6.3.9600.0"
                       // VS (Russian):
                       //    Microsoft Visual Studio Professional&nbsp;2019
                       //    Версия 16.11.9

There is another theme with this error, but it closed:
https://developercommunity2.visualstudio.com/t/DirectoryGetDirectoriesdrive-return-a/175411?entry=suggestion&space=8&preview2=true

---

Original Comments

Feedback Bot on 3/21/2022, 00:32 AM:

(private comment, text removed)

Author:	vsfeedback
Assignees:	-
Labels:	area-System.IO, untriaged
Milestone:	-

[skyoxZ]

I tested the code below and got an amazing result:

using System;
using System.IO;

for(int i = 0;i < 20; i++)
{
    string s = (char)('A' + i) + ":";
    Console.WriteLine(s + " -> " + Path.GetFullPath(s));
}

Output:

A: -> A:\
B: -> B:\
C: -> C:\WINDOWS\System32
D: -> D:\vs projects\ConsoleApp1\ConsoleApp1\bin\Debug\net6.0
E: -> E:\
F: -> F:\
G: -> G:\
...

[svick]

This is called a drive relative path and it's why the backslash in D:\ is important. For more details, see the article on Windows paths.

[skyoxZ]

This is called a drive relative path and it's why the backslash in D:\ is important. For more details, see the article on Windows paths.

I read the article but still don't understand what happened exactly. And I think the behavior in this issue is definitely unexpected.

Update: I understand my case now and believe D:\ref is a bug.

[svick]

I understand my case now and believe D:\ref is a bug.

I think you're right. Returning the ref directory is correct. But returning it as D:\ref is incorrect. Instead, I think it should be returned as D:ref in this case.

[jozkee]

dirSSS[0]; // Output: "D:\ref"
Environment.Version; // "5.0.13" (Net Core)
Environment.OSVersion; // "Microsoft Windows NT 6.3.9600.0"

I wonder if this bug is specific to Windows 8.1, in such case it would probably be tied to the Windows API, not to .NET.
I couldn't repro it on windows 10.

Directory.GetDirectories("C:") does yield the right results for me (folders of the current working directory).

[jozkee]

@skyoxZ linking issue related to your comments: #63892.

[skyoxZ]

@jozkee I did repro the D:\ref issue on my Win 11.
May give more info about 3 days later (I'm on holiday).

[jozkee]

@skyoxZ yes please, could you please also add Console.WriteLine(Environment.CurrentDirectory); to your repro. I want to discard that the cwd is indeed different to what's being used in GetDirectories.

[skyoxZ]

@jozkee Please try the code below:

string foo = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "foo");
string bar = Path.Combine(foo, "bar");
Directory.CreateDirectory(bar);
Environment.CurrentDirectory = foo;
string root = foo.Remove(2);
string[] ss = Directory.GetDirectories(root);
Console.WriteLine("-- " + root);
foreach(string s in ss)
{
    Console.WriteLine(s);
}

.NET Framework 4.8 got correct result:

-- D:
D:bar

however, .NET 6.0 got the result below:

-- D:
D:\bar