Are there any multipolygons in my shapefile?

Question

In QGIS 2.x, is there a simple way to determine if a polygons layer contains multipolygon geometries and if yes: which are these features?

Answer 1

The Topology Checker plugin has an option to check if a layer contains multipart geometries.

It is also possible to highlight multipart geometries.

Answer 2

Not tested but perhaps use something like this in the Python Console:

layer = qgis.utils.iface.activeLayer()
geom = QgsGeometry()
if layer.wkbType() == QGis.WKBMultiPolygon:
    for feature in layer.getFeatures(): 
        if geom.isMultipart():
            print feature.id()