Improve whitespace consistency of output labels

[LandingEllipse]

Whitespace and indentation issues are observed here and there when using Passthrough. This issue is a place to collect reproducible snippets which can be investigated further.

Non-fetch multi

Template:

    <A pt:fetch="false()" pt:sources="template">
        <B pt:multi="2">
            <c pt:fill="pt:sequence('c one', 'c two')"/>
        </B>
    </A>

Output:

    <A>
        <B>
            <c>c one</c>
        </B>
    <B>
            <c>c two</c>
        </B>
    </A>

It's likely a tail issue, as adding in a following sibling:

    <A pt:fetch="false()" pt:sources="template">
        <B pt:multi="2">
            <c pt:fill="pt:sequence('c one', 'c two')"/>
        </B>
        <d>I've got 'chu</d>
    </A>

Fixes the issue:

    <A>
        <B>
            <c>c one</c>
        </B>
        <B>
            <c>c two</c>
        </B>
        <d>I've got 'chu</d>
    </A>