Don't use QString::toAscii().
Don't use QString::toAscii().

RevBy: Jan Arne Petersen

It is said that it is broken in Qt4. And also it is deprecated in
Qt5. QString::toLatin1() is recommended instead.

Full, original commit at c7563791c7b3d8e1369caf70544c60e1fde7ea65 in maliit-framework

maliit/inputcontext-qt4,perencia/inputcontext-qt4,maliit/inputcontext-qt4