This is a not-for-merge branch to demonstrate:

• Bug on master as reported in [Bug]: Variables from one layout overwrite the ones in the current layout #9710 by @ror3d.

• That layouts as on master do not merge front matter data from ancestor layouts as expected by @parkr in following comments:

  If you don't merge the layout data, you don't get all of that metadata available in one place. Sometimes you'd want to access the entire collection of layout metadata all in one place...
      — First Comment
  the thing I was thinking of was inheriting (by design) from a parent layout in the tree...
      — Subsequent comment