HTML5: Modifier bug?

[[-hh]]

We cannot enter into HTML5 standalone fields

backquote (`), tilde(~), singleQuote('), quote(") and circumflex(^).

with an US-International PC-keyboard. Quotes work with a German keyboard.
This is probably the basic HTML5 "modifier-bug".

You could use (built with 9.0.0 this is the same in LC 9.5.0)
http://hyperhh.de/html5/javaScriptTest- ... -4hhX.html
for testing:
The input field in the browser has no errors, but the text field in the standalone.
This is the same when the field uses an enclosed "full" UTF-8 font.

Reported as bug #22324.