Potential listview CSS regression

[rzhao271]

I opened the Settings editor, hovered over a setting, and noticed a new grey line appear to the left of the settings.

This issue occurs with the default light and dark themes.

[rebornix]

I found that when calling updateOptions, if we don't pass in the style override anymore, it will be reset to default

vscode/src/vs/workbench/contrib/preferences/browser/settingsTree.ts

Lines 2303 to 2304 in 3fd6567

	if (e.affectsConfiguration('workbench.list.smoothScrolling')) {
	this.updateOptions({

I put this fix for notebook 6d6d9bd but I wonder if it's unexpected @aeschli

[aeschli]

Thanks @rebornix for figuring that out. We shouldn't update options that are not set, that a regression.
I fixed that with #171797 and updated your code to back what it was.

@rzhao271 Is different, it's about the indent guides which were disabled previously by not providing any colors. With my change we complete your colors with the default colors, which IMO is the right thing to do.
#171809 is a simple fix.
But I think we should not use the colors for that but the already existing option.
I'm working on a follow up PR, but that needs to be reviewed by @joaomoreno who is out today.