With revision recording on, setContent inserted the whole file in one
transaction, so the recorder marked every run as the reader's own
insertion — the document then rendered underlined in the author colour
(#c69200) from the first character. Measured: 19 843 of 19 843 characters
on an 11-page import, 436 revision spans.
Both loads (new document, import) now carry the RECORDING meta; what is
typed after the open is still recorded, as in both word processors.