theme/powerline: fix error scm: parameter not defined

[NariyasuHeseri]

Fix bug that powerline theme's scm feature does not work.

Description

The commit 2991aa6 removed set +u
but still references the variable scm without defining it.
This commit remove the reference to scm.

Motivation and Context

This makes powerline theme's scm feature work again.

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• If my change requires a change to the documentation, I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• If I have added a new file, I also added it to clean_files.txt and formatted it using lint_clean_files.sh.
• I have added tests to cover my changes, and all the new and existing tests pass.

[gaelicWizard]

Looks like that may have been some vestige of a much older variable. I don't think it's defined anywhere, let alone anywhere near here.

Thanks for catching that!

[davidpfarrell]

Hi all - Let's not merge this yet - I use this theme and have never received the error that would result from ${scm?} not being defined ... I want to dive into this a bit (maybe look at the revision history) and see how we got here ...

Thanks for bringing it up !

[NariyasuHeseri]

Hi all - Let's not merge this yet - I use this theme and have never received the error that would result from ${scm?} not being defined ... I want to dive into this a bit (maybe look at the revision history) and see how we got here ...

Thanks for bringing it up !

Probably it's because you have set set +u in your .bashrc or by your bash installation?

[davidpfarrell]

OK!

Looks like this bug was introduced by @edubxb in #815 which was a nice refactor that enabled the configurable segment_prompt feature !

There is a scm function in base.theme.bash (link is version from time of #815)
Wonder if that ${scm} was a leftover WIP on the PR that was initially invoking the function directly?

Either way, I feel a lot more confident about removing it now, so thanks for holding off!