View headerBorder is not applied consistently

[bpasero]

This seems to be a long regression from #32003 that now surfaces stronger since I introduced a new color sideBarSectionHeader.border (from #36674). Once set (e.g. to red), notice how the color is not applied in some viewlets for the second view or wrongly for the first view:

Explorer (after a reload)

Extensions (wrongly shows it for first view)

[sandy081]

@bpasero May I know how it is a regression? I think the new colour you added is not completely implemented.

Looking at the implementation, new colour is added only from second view. But there is missing implementation to remove/add the colour of existing view when a view is added or removed on the top.

[bpasero]

@sandy081 you refer to this I guess which does not seem to be dynamic:

https://github.com/Microsoft/vscode/blob/5f53ed3811e59abc9935fb73953dc6730991789e/src/vs/workbench/browser/parts/views/panelViewlet.ts#L326

[sandy081]

@bpasero Yes.