T6058: Fix popen command wrapper handling

[HollyGurza]

Ensure wrapper is only prepended to command when it is non-empty

Change summary

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

• https://vyos.dev/T6058

Related PR(s)

How to test / Smoketest result

conf
set system proxy port '3128'
set system proxy url 'http://127.0.0.1'
set system config-management commit-archive location 'git+https://user:[email protected]/user/commit-archive'
commit

before fix:

# commit
Archiving config...
  git+https://gitlab.com/user/commit-archive Unable to upload "git+https://user:[email protected]/user/commit-archive/config.boot-vyos.20250205_052044": [Errno 2] No such file or directory: " ['git', 'clone', 'https://user:[email protected]/user/commit-archive', '/tmp/git-commit-archive-22hte0rg/repository', '--depth=1']"
run-parts: /etc/commit/post-hooks.d/02vyos-commit-archive exited with return code 1

after fix:

vyos@vyos# commit
Archiving config...
  git+https://gitlab.com/user/commit-archive [edit]
vyos@vyos# 

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[dmbaturin]

The fix is good, but I find the PR title misleading. The issue with commit archive is a manifestation of this bug, but the bug is not unique to commit archive — it may already have other effects in someone's code. Please adjust the title to make accurately describe what the fix is, then I'll approve it.

[github-actions]

CI integration ❌ failed!

Details

CI logs

• CLI Smoketests (no interfaces) ❌ failed
• CLI Smoketests (interfaces only) 👍 passed
• Config tests 👍 passed
• RAID1 tests 👍 passed
• TPM tests 👍 passed