Arabic text line with space tail can lead line head exceed.

Multiline arabic text with space at the tail of each line can lead the line head exceed.

The attachment `arabic-bad.txt` show the wrong effect, while `arabic-ok.txt` show the correct effect.

You can just use a QML `Text` to test it.(while i don't know why when using QtCreator, the bad arabic text cannot copyed to the editor by Ctrl-C/Ctrl-V, it will missing the `Space` character. So my test program get the string by reading a txt file).