b-table sticky header broken if sortable (fixes #6961)

[m-mohr]

Describe the PR

My naive approach at fixing #6961 so that b-table sticky header is sticky again.

PR checklist

What kind of change does this PR introduce? (check at least one)

• [x] Bugfix (fixes a boo-boo in the code) - fix(...), requires a patch version update
• [ ] Feature (adds a new feature to BootstrapVue) - feat(...), requires a minor version update
• [ ] Enhancement (augments an existing feature) - feat(...), requires a minor version update
• [ ] ARIA accessibility (fixes or improves ARIA accessibility) - fix(...), requires a patch or minor version update
• [ ] Documentation update (improves documentation or typo fixes) - chore(docs), requires a patch version update
• [ ] Other (please describe)

Does this PR introduce a breaking change? (check one)

• [x] No
• [ ] Yes (please describe since breaking changes require a minor version update)

The PR fulfills these requirements:

• [x] It's submitted to the dev branch, not the master branch
• [x] When resolving a specific issue, it's referenced in the PR's title (i.e. [...] (fixes #xxx[,#xxx]), where "xxx" is the issue number)
• [x] It should address only one issue or feature. If adding multiple features or fixing a bug and adding a new feature, break them into separate PRs if at all possible.
• [ ] The title should follow the Conventional Commits naming convention (i.e. fix(alert): not alerting during SSR render, docs(badge): update pill examples, chore(docs): fix typo in README, etc.). This is very important, as the CHANGELOG is generated from these messages, and determines the next version type (patch or minor). - Done through GitHub Web so can't change the commit message anymore.

If new features/enhancement/fixes are added or changed:

• [ ] Includes documentation updates
• [ ] Includes component package.json meta section updates (prop, slot and event changes/updates)
• [ ] Includes any needed TypeScript declaration file updates
• [ ] New/updated tests are included and passing (required for new features and enhancements)
• [ ] Existing test suites are passing
• [ ] CodeCov for patch has met target (all changes/updates have been tested)
• [ ] The changes have not impacted the functionality of other components or directives
• [ ] ARIA Accessibility has been taken into consideration (Does it affect screen reader users or keyboard only users? Clickable items should be in the tab index, etc.)

If adding a new feature, or changing the functionality of an existing feature, the PR's description above includes:

• [ ] A convincing reason for adding this feature (to avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it)

[vercel[bot]]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Updated
bootstrap-vue	✅ Ready (Inspect)	Visit Preview	Jan 3, 2023 at 1:52PM (UTC)

[codesandbox-ci[bot]]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 3ccab698db9b8fb2c7dd22dce4909b338103d719:

Sandbox	Source
BootstrapVue Starter Project	Configuration
BootstrapVue Nuxt.js Starter Project	Configuration

[m-mohr]

Could anyone have a look at this?

[m-mohr]

Any news on this? This fixes a regression....

[codecov[bot]]

Codecov Report

Merging #7023 (3ccab69) into dev (c597779) will not change coverage. The diff coverage is 100.00%.

@@            Coverage Diff            @@
##               dev     #7023   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          305       305           
  Lines        10452     10453    +1     
  Branches      2550      2551    +1     
=========================================
+ Hits         10452     10453    +1     

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/components/table/helpers/mixin-thead.js	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[VividLemon]

You should include a test case for this

[m-mohr]

I'm not sure how I can cover this with tests, sorry.

[adsonvinicius]

I tested here and it's broken when sortable. I had to downgrade to 2.21.2 to make it work again.