QMimeData::hasImage reports true while imageData is null

I have very similar bug to QTBUG-31069 but on Linux.

What I do..
I have overrriden QTextEdit::insertFromMimeData and from its handler I do

QImage img(qvariant_cast<QImage>(data->imageData()));

data->hasImage() always reports true when I copied an image. but the `img` variable is usually always null.

For example if I copy an image to the clipboard and start pressing ctrl+v repeatedy then likely only once of 10 times img won't be null.

If I insert to some other app like Gimp it's always inserted properly.

Formats reported by mimedata for every insert attempts (no difference when succeed)

("TIMESTAMP", "TARGETS", "SAVE_TARGETS", "MULTIPLE", "image/png", "text/html", "application/x-qt-image")