Preferences > User Interface > Open Documents As Tabs was stored but did
nothing. With the box cleared, each document opened or created afterwards
opens in a floating window of its own, at the next cascade place, as
Window > Arrange > Float in Window floats it. Documents already open, and
documents open when the app starts, keep their tabs; checking the box
again leaves floating documents in their windows.
The engine records the preference on each document as it opens
(DocState::opened_as_tab), and the UI finds new documents by uid, so a
command batch that closes and opens documents, or changes the preference
between opening them, places each one as the preference was when it
opened.
Undo, Redo and a canceled undo group put back an earlier document but
left the Variables panel highlight as it was. After renaming the
highlighted variable and undoing, the highlight still named the new
name: a variable defined later under that name showed highlighted
without a click, and Delete removed it.
Each of these paths now clears a highlight whose variable the restored
document does not define, as Delete Variables and Load Variable Library
already did.
dotCooCoo