doc_create with from=text wrote every character outside WinAnsiEncoding
(Korean, Chinese, Japanese, emoji) as `?` with no error. It now refuses
such text with the same message page_add_text already gives, naming the
first undrawable character and its code point. Line breaks, page breaks
and tabs are layout and still pass. create_from_text itself is unchanged,
so opening .txt files, comment summaries and compare reports behave as
before.
Shukat Ibrahim
2fbce7028c