We have explicit QFont properties, and QTextFormat::setProperty().
Setting FontFixedPitch doesn't necessarily affect the view (QTextEdit or
Qt Quick Text/TextEdit); and setting the font to the one we get from
QFontDatabase::systemFont(QFontDatabase::FixedFont) is also unreliable,
because the "monospace" fallback might actually be proportional.
QTextMarkdownWriter checks for both to decide whether to use backticks;
so markdown writing works if an editor UI makes the format monospace
both ways to be safe. But in the opposite case that the main font is
actually a monospace font, it's always been broken.
The rest of the QTextCharFormat properties are generally working, to
the extent that they are applicable to Markdown. But we lacked explicit
test coverage: so far we were just reading Markdown or HTML and writing
Markdown to test the writer.
Also amend an old comment about writing underlines: writing was always
possible, and since f5c7799f59 reading is
supported too. So the underline support is symmetric (except that we
don't heed the QTextDocument::MarkdownFeatures argument to the writer
ctor: we probably should do that some day).
Pick-to: 6.7
Task-number: QTBUG-54623
Task-number: QTBUG-75648
Task-number: QTBUG-75649
Task-number: QTBUG-79900
Task-number: QTBUG-99676
Task-number: QTBUG-103484
Change-Id: Iacb4ed0ea59030570702d4eadfdadfad872065c6
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>