QGIS 3.4: My project uses Pseudo Mercator as the CRS (datum: WGS 1984). I now added a shapefile which uses a local coordinate system from Austria (datum: MGI). I did not define a datum transformation in the general QGIS settings, neither did i define a datum transformation in the project settings->CRS (it is empty).
I would expect that no transformation is used and that there is an offset between my map and the shapefile (like in ArcGIS), but the shapefile aligns correctly with my background map (which is Pseudo Mercator, like the project CRS).
I assume that there is a default transformation, even if I did not define anything, but where can I see the default datum transformation or how does QGIS deal with that?