From 9293c3d857123bdf41b74ea4ade7311be3a1c05b Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Tue, 4 Jan 2022 13:27:37 -0700
Subject: [PATCH] Fix a bug in FE_Face.

---
 source/fe/fe_face.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/fe/fe_face.cc b/source/fe/fe_face.cc
index bed160f792..79c9797f1d 100644
--- a/source/fe/fe_face.cc
+++ b/source/fe/fe_face.cc
@@ -956,7 +956,7 @@ FE_FaceP<dim, spacedim>::get_subface_interpolation_matrix(
           for (unsigned int k = 0; k < face_quadrature.size(); ++k)
             {
               const Point<dim - 1> p =
-                numbers::invalid_unsigned_int != 0u ?
+                subface == numbers::invalid_unsigned_int ?
                   face_quadrature.point(k) :
                   GeometryInfo<dim - 1>::child_to_cell_coordinates(
                     face_quadrature.point(k), subface);
-- 
2.39.5