QString::arg(double) inconsistent rounding

Hello,

QString::arg() uses number flooring and ceiling inconsistently.

Have a look at the following table where the
1st column is the double used as argument of the arg() method
2nd column, the result of QString("%1").arg(myDouble, 0, 'G', 3);

qDebug() << QString("%1").arg(myDouble, 0, 'e', 20) << QString("%1").arg(myDouble, 0, 'G', 3);

"1.08500000000000000000e+02" "108"
"1.09500000000000000000e+02" "110"
"1.10500000000000000000e+02" "110"
"1.11500000000000000000e+02" "112"
"1.12500000000000000000e+02" "112"
"1.13500000000000000000e+02" "114"

The 2nd column is not rounded consistently:
108.5 is presented as 108 expected 109 KO
109.5 is presented as 110 expected 110 OK

Same exercise with arg(myDouble, 0, 'G', -1):

qDebug() << QString("%1").arg(myDouble, 0, 'e', 20) << QString("%1").arg(myDouble, 0, 'G', -1);
"1.11108500000000000000e+05" "111108"
"1.11109500000000000000e+05" "111110"
"1.11110500000000000000e+05" "111110"
"1.11111500000000000000e+05" "111112"
"1.11112500000000000000e+05" "111112"
"1.11113500000000000000e+05" "111114"