Hexadecimal Unicode text input broken

Hi, if you enable hexadecimal Unicode text input in WIndows by following the guide in https://en.wikipedia.org/wiki/Unicode_input ,the relevant part is here:

Hexadecimal Unicode input can be enabled by adding a string type (REG_SZ) value called EnableHexNumpad to the registry key HKEY_CURRENT_USER\Control Panel\Input Method and assigning the value data 1 to it.

then you can enter Unicode characters this way:

press the ALT key and then press the + key on the numeric keypad, then while holding the ALT key down press the desired hexadecimal digits. When you're done let go of the ALT key.

If you start Notepad on a Windows PC that has that registry key as described above, then you can enter for example Unicode Left Arrow by typing ALT and + on the numeric keypad and then typing 2190 while holding down the ALT key. A left arrow should now appear in Notepad.

If you create a vanilla Widgets app in Qt on the same PC and then insert a QLineEdit in mainwindow, you can use the same procedure for entering the Unicode Left Arrow into it, but only if you use the digits on the numeric keypad and not the digits above the letters on the keyboard. If you happen to use the digits above the letters they will display as "junk"/extra digits before the Left Arrow is shown.

But if you need to type the letters A-F, for example when entering a Unicode Leftwards White Arrow U+21E6, then even if you keep using the numeric digits on numeric keypad, the letter E will always display in the QLineEdit before the white arrow appears.

Note that those "junk" digits or letters A-F are not displayed in Notepad or similar programs in Windows like Wordpad, so this I think is a bug in Qt's keyboard handling.

For more, see the forum discussion https://forum.qt.io/topic/109968/barcode-reader-with-unicode-chars