From 2a0c03b244ef9f641fe959d026225d49dd007a14 Mon Sep 17 00:00:00 2001
From: Pablo Brubeck <brubeck@protonmail.com>
Date: Mon, 6 Jan 2025 17:35:03 -0600
Subject: [PATCH] style

---
 firedrake/bcs.py                                  | 2 +-
 firedrake/formmanipulation.py                     | 2 +-
 tests/firedrake/equation_bcs/test_equation_bcs.py | 1 -
 3 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/firedrake/bcs.py b/firedrake/bcs.py
index 7c6821b3e3..5884907feb 100644
--- a/firedrake/bcs.py
+++ b/firedrake/bcs.py
@@ -635,7 +635,7 @@ def reconstruct(self, field=None, V=None, subu=None, u=None, row_field=None, col
             rank = len(self.f.arguments())
             splitter = ExtractSubBlock()
             form = splitter.split(self.f, argument_indices=(row_field, col_field)[:rank])
-            if form == 0:
+            if isinstance(form, ufl.ZeroBaseForm) or form.empty():
                 # form is empty, do nothing
                 return
             if u is not None:
diff --git a/firedrake/formmanipulation.py b/firedrake/formmanipulation.py
index 5e92bd8e8a..97f2b3c43e 100644
--- a/firedrake/formmanipulation.py
+++ b/firedrake/formmanipulation.py
@@ -73,8 +73,8 @@ def split(self, form, argument_indices):
             assert (len(idx) == 1 for idx in self.blocks.values())
             assert (idx[0] == 0 for idx in self.blocks.values())
             return form
-        f = map_integrand_dags(self, form)
         # TODO find a way to distinguish empty Forms avoiding expand_derivatives
+        f = map_integrand_dags(self, form)
         if expand_derivatives(f).empty():
             # Get ZeroBaseForm with the right shape
             f = ZeroBaseForm(tuple(Argument(subspace(arg.function_space(),
diff --git a/tests/firedrake/equation_bcs/test_equation_bcs.py b/tests/firedrake/equation_bcs/test_equation_bcs.py
index 3929eeaddb..fdd05b7f2e 100644
--- a/tests/firedrake/equation_bcs/test_equation_bcs.py
+++ b/tests/firedrake/equation_bcs/test_equation_bcs.py
@@ -190,7 +190,6 @@ def linear_poisson_mixed(solver_parameters, mesh_num, porder):
 
     solve(a == L, w, bcs=[bc2, bc3, bc4], solver_parameters=solver_parameters)
 
-
     f = cos(2 * pi * x + pi / 3) * cos(2 * pi * y)
     g = as_vector([-2 * pi * sin(2 * pi * x + pi / 3) * cos(2 * pi * y), -2 * pi * cos(2 * pi * x + pi / 3) * sin(2 * pi * y)])