QIcon::addPixmap() creates an icon engine when not yet available. During
the initialization, the filename of the image is already passed to the
icon engine and some (e.g. svg icon engine) already loads it. Afterwards
the image is loaded again with addFile(). Avoid this by checking if the
ctor of the icon engine already loaded the file and don't call addFile()
afterwards in this case.
Fixes: QTBUG-8151
Change-Id: I9289f17e5d703c08a82ce51ce8bded70feb6f82d
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
60061f679c