Unicode symbols not being displayed in widgets

AndyBrice · wrote on 25 Nov 2021, 11:19

I have a string containing the Unicode character (U+FFFC or \ufffc).

If I call QFontMetrics::InFont( QChar ) on the character it returns true.

If I call QFontMetrics::horizontalAdvance( QChar ) on the character it returns 24.

But nothing is displayed for this character in my QTableView for any of the major fonts. Not even a space. It appears to be 0 width. Other characters display fine.

Is this a known bug?

This is a problem with Qt 5.15.2 on Windows 10 and Qt 5.15.2 on macOS 12.01.

AndyBrice · wrote on 25 Nov 2021, 15:15

Here you can see the same text containing QChar( 0xFFFC ) characters is displayed differently via QLineEdit (spaces), QTextView (0 width) and qDebug (? chars).

I have added this to the Qt bug database as:
https://bugreports.qt.io/browse/QTBUG-98645
I have attached example code there.