Fix FormSum weights

ufl/action.py

@@ -69,12 +69,21 @@ def __new__(cls, *args, **kw):
         if isinstance(right, (Coargument, Argument)):
             return left
 
-        if isinstance(left, (FormSum, Sum)):
-            # Action distributes over sums on the LHS
-            return FormSum(*[(Action(component, right), 1) for component in left.ufl_operands])
-        if isinstance(right, (FormSum, Sum)):
-            # Action also distributes over sums on the RHS
-            return FormSum(*[(Action(left, component), 1) for component in right.ufl_operands])
+        # Action distributes over sums on the LHS
+        if isinstance(left, Sum):
+            return FormSum(*((Action(component, right), 1) for component in left.ufl_operands))
+        elif isinstance(left, FormSum):
+            return FormSum(
+                *((Action(c, right), w) for c, w in zip(left.components(), left.weights()))
+            )
+
+        # Action also distributes over sums on the RHS
+        if isinstance(right, Sum):
+            return FormSum(*((Action(left, component), 1) for component in right.ufl_operands))
+        elif isinstance(right, FormSum):
+            return FormSum(
+                *((Action(left, c), w) for c, w in zip(right.components(), right.weights()))
+            )
 
         return super(Action, cls).__new__(cls)
 

ufl/adjoint.py

@@ -49,7 +49,7 @@ def __new__(cls, *args, **kw):
             return form._form
         elif isinstance(form, FormSum):
             # Adjoint distributes over sums
-            return FormSum(*[(Adjoint(component), 1) for component in form.components()])
+            return FormSum(*((Adjoint(c), w) for c, w in zip(form.components(), form.weights())))
         elif isinstance(form, Coargument):
             # The adjoint of a coargument `c: V* -> V*` is the identity
             # matrix mapping from V to V (i.e. V x V* -> R).

ufl/algorithms/map_integrands.py

@@ -59,7 +59,7 @@ def map_integrands(function, form, only_integral_type=None):
             # Simplification of `BaseForm` objects may turn `FormSum` into a sum of `Expr` objects
             # that are not `BaseForm`, i.e. into a `Sum` object.
             # Example: `Action(Adjoint(c*), u)` with `c*` a `Coargument` and u a `Coefficient`.
-            return sum([component for component, _ in nonzero_components])
+            return sum(component * w for component, w in nonzero_components)
         return FormSum(*nonzero_components)
     elif isinstance(form, Adjoint):
         # Zeros are caught inside `Adjoint.__new__`