Allows setting symbols other map item sizes to Map Units in Meters. This allows setting the size always in meters, regardless of what the underlying map units are (e.g. they can be it geographic degrees). The size in meters is calculated based on the current project ellipsoid setting and a projection of the distances in meters at the center of the current map extent.
Original commit: https://github.com/qgis/QGIS/commit/172e80918131bb8414c753a463a9b7abc069e0bf by nyalldawson
Allows setting symbols other map item sizes to Map Units in Meters. This allows setting the size always in meters, regardless of what the underlying map units are (e.g. they can be it geographic degrees). The size in meters is calculated based on the current project ellipsoid setting and a projection of the distances in meters at the center of the current map extent.