'map_join'-variable is lost after stat is applied

[OLarionova-HORIS]

Use a pie as an example, where the 'count2d' stat is applied by default

coords = pd.DataFrame( {'City': ['A', 'B'], 'x': [-80, 80], 'y': [-40, 40]} )
gdf = geopandas.GeoDataFrame(coords, geometry=geopandas.points_from_xy(coords.x, coords.y))

df = {
    "Name": ["A", "A", "B", "B"],
    "FullName": ["CityA", "CityA", "CityB", "CityB"],
    "Vote": ["Yes", "No", "Yes", "No"],
    "Number": [120, 30, 20, 80 ]
}

ggplot() + geom_pie(aes(fill='Vote', weight='Number', group='FullName'), 
                    data=df, map=gdf, map_join=['Name','City'])

Out:

Variable not found: 'Name'. Variables in data frame: ['Vote', '..y..', 'FullName', '..count..', '..x..']

[OLarionova-HORIS]

Fixed: 1e911d5