Qt CSS: gradient on text restarts after every upper-case letter with small-caps

If a gradient is set on a text with a stylesheet, the gradient apply to the whole text.
If there is a font-variant "small-caps", the gradient restart for each upper-case letter.

To reproduce the problem, compare the two following stylesheet in Designer:
QLabel {
font-variant: small-caps;
color: qlineargradient(spread:pad, x1:0, y1:0, x2:1, y2:0, stop:0 rgba(0, 0, 0, 255), stop:1 rgba(255, 255, 255, 255));
}

and
QLabel {
color: qlineargradient(spread:pad, x1:0, y1:0, x2:1, y2:0, stop:0 rgba(0, 0, 0, 255), stop:1 rgba(255, 255, 255, 255));
}