Incorrect ownership when creating files using MSYS2 commands as Administrator

[fgimian]

Description / Steps to reproduce the issue

1. Install MSYS2
2. Search for MSYS2 in your start menu, right-click and start any of the environments as Administrator
3. Create a file in your home directory with touch example.txt
4. Open the location in Windows Explorer, select example.txt, hit Alt+Enter, select the Security tab and then click Advanced, notice the owner of the file is your username and not the Administrators group

When using any suitable tool to create a file in Command Prompt and PowerShell as Administrator, the owner of the file is the Administrators group as expected.

This problem also goes for any command executed through the bash shell built as part of MSYS2 as well and can result in unexpected behaviour when CLI tools expect that creation of files in an elevated context will be owned by the Administrators group.

Expected behavior

Any file created in a privileged window would be owned by the Administrators group, matching Command Prompt, PowerShell and Windows Explorer.

Actual behavior

Files created using any tools compiled for MSYS2 in a privileged window are owned by the user account, not the Administrators group.

Verification

• I have verified that my MSYS2 is up-to-date before submitting the report (see https://www.msys2.org/docs/updating/)

Windows Version

MSYS_NT-10.0-26100

Are you willing to submit a PR?

I'm unaware how to rectify this issue I'm afraid.

[fgimian]

Here's a demonstration using PowerShell running as Administrator. Even without being in the MSYS2 Bash shell, executing touch results in incorrect permissions.

PS C:\Users\Fots\Downloads\example> New-Item file-powershell.txt


    Directory: C:\Users\Fots\Downloads\example


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a----        24/12/2024   8:58 PM              0 file-powershell.txt


PS C:\Users\Fots\Downloads\example> C:\msys64\usr\bin\touch.exe file-msys2.txt
PS C:\Users\Fots\Downloads\example> Get-Acl -Path .\file-powershell.txt


    Directory: C:\Users\Fots\Downloads\example


Path                Owner                  Access
----                -----                  ------
file-powershell.txt BUILTIN\Administrators NT AUTHORITY\SYSTEM Allow  FullControl...


PS C:\Users\Fots\Downloads\example> Get-Acl -Path .\file-msys2.txt


    Directory: C:\Users\Fots\Downloads\example


Path           Owner           Access
----           -----           ------
file-msys2.txt FOTSIES-PC\Fots NT AUTHORITY\SYSTEM Allow  FullControl...

Kindly let me know if I can provide any further information or if I'm missing something 😄

Thanks heaps!
Fotis

[jeremyd2019]

I'm guessing Cygwin does this on purpose, to act more like POSIX.