wslview fails when registry access is disabled

[jaknz]

Windows Version

Windows 11

Windows Build Number

22621.2428

WSL Version

WSL 2

Distro Version

Debian 12

WSL Utilities Version

4.1.1

Describe the bug

On a corporate GPO-managed Windows workstation where group policy prohibits access to the registry, multiple calls to reg.exe fail with errors, leading to internal failures in the utility and broken functionality. Pages do load in my Windows browser, so obviously these calls to the registry aren't core to the functionality. Would be really great to either not depend on REG at all, or have an option flag to not check whatever it is trying to check.

Steps to Reproduce

$ wslview "http://github.com"

Expected behavior

Script runs quietly and launches Windows web browser, without several lines of error messages.

Additional context

Error stream output from script:

ERROR: Registry editing has been disabled by your administrator.
ERROR: Registry editing has been disabled by your administrator.
ERROR: Registry editing has been disabled by your administrator.
/usr/bin/wslview: line 267: [: : integer expression expected
Parameter format not correct - ""
Cannot find an overload for "GetEncoding" and the argument count: "0".
At line:1 char:59
+ ... ing]::UTF8; [Console]::InputEncoding = [System.Text.Encoding]::GetEnc ...
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodException
    + FullyQualifiedErrorId : MethodCountCouldNotFindBest

/usr/bin/wslview: line 270: [: : integer expression expected

Code of Conduct

• I agree to follow this project's Code of Conduct

[jaknz]

I found the --debug flag in the code for slightly more info:

[debug:/usr/bin/wslview] Showing debug output.
[debug:/usr/bin/wslview] source default setting
[debug:/usr/bin/wslview] /etc/wslu/conf found, sourcing
ERROR: Registry editing has been disabled by your administrator.
[debug:/usr/bin/wslview] distro: debian
[debug:/usr/bin/wslview] lname: https://github.com
[debug:/usr/bin/wslview] WSLVIEW_DEFAULT_ENGINE: powershell
ERROR: Registry editing has been disabled by your administrator.
[debug:/usr/bin/wslview] properfile_full_path:
[debug:/usr/bin/wslview] validating whether if it is a link
[debug:/usr/bin/wslview] It is a link
[debug:/usr/bin/wslview] cmd: "https://github.com"
[debug:/usr/bin/wslview] winps_exec: called with command Start "https://github.com"
ERROR: Registry editing has been disabled by your administrator.
/usr/bin/wslview: line 267: [: : integer expression expected
Parameter format not correct - ""
Cannot find an overload for "GetEncoding" and the argument count: "0".
At line:1 char:59
+ ... ing]::UTF8; [Console]::InputEncoding = [System.Text.Encoding]::GetEnc ...
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodException
    + FullyQualifiedErrorId : MethodCountCouldNotFindBest

/usr/bin/wslview: line 270: [: : integer expression expected

[jaknz]

I've been walking through the code to see what can be done without checking the registry. Looks like the biggest offender is getting the Windows build number. I've found a reliable fallback which I've patched into my installed version, and it's much quieter, but not completely error-free.

build=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/WindowsPowerShell/v1.0/powershell.exe /c "(gcm wsl).Version.Build" | sed -e 's|\r||g')

[jaknz]

It also looks like the codepage variable isn't being set which is causing the Powershell errors. This can also be handled by (ironically) calling Powershell as above:

cp=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/WindowsPowerShell/v1.0/powershell.exe /c "Get-ItemPropertyValue HKLM:\SYSTEM\CurrentControlSet\Control\Nls\CodePage -Name OEMCP" | sed -e 's|\r||g')

[jaknz]

And with those two patches, I'm not hitting reg.exe, and thus getting a clean run. Note that I added a couple of debug_echo commands to check that I'm getting the correct build and codepage with these new methods.

wslview --debug "http://github.com"
[debug:/usr/bin/wslview-patch] Showing debug output.
[debug:/usr/bin/wslview-patch] source default setting
[debug:/usr/bin/wslview-patch] /etc/wslu/conf found, sourcing
[debug:/usr/bin/wslview-patch] build: 22621
[debug:/usr/bin/wslview-patch] distro: debian
[debug:/usr/bin/wslview-patch] lname: http://github.com
[debug:/usr/bin/wslview-patch] WSLVIEW_DEFAULT_ENGINE: powershell
[debug:/usr/bin/wslview-patch] build: 22621
[debug:/usr/bin/wslview-patch] properfile_full_path:
[debug:/usr/bin/wslview-patch] validating whether if it is a link
[debug:/usr/bin/wslview-patch] It is a link
[debug:/usr/bin/wslview-patch] cmd: "http://github.com"
[debug:/usr/bin/wslview-patch] winps_exec: called with command Start "http://github.com"
[debug:/usr/bin/wslview-patch] build: 22621
[debug:/usr/bin/wslview-patch] codepage: 850