Merge branch 'bugfix/system-component-iteration' into 'master'

[bugfix] Correctly iterate over children of MixedElement

See merge request !171

python/dune/perftool/pdelab/localoperator.py

@@ -334,7 +334,7 @@ def _list_infos(expr, number, visitor):
     elif visitor.measure == "interior_facet":
         restrictions = (Restriction.NEGATIVE, Restriction.POSITIVE)
     for res in restrictions:
-        for ei in range(element.num_sub_elements() + 1):
+        for ei in range(element.value_size()):
             yield PDELabAccumulationInfo(element_index=ei, restriction=res)