From: Martin Kronbichler <kronbichler@lnm.mw.tum.de>
Date: Thu, 14 Nov 2019 09:18:31 +0000 (+0100)
Subject: Fix bug in MappingQGeneric::transform_real_to_unit_cell
X-Git-Tag: v9.2.0-rc1~874^2~3
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aa74f5c1b1dd2b5a559591bf490860cbd8cdb927;p=dealii.git

Fix bug in MappingQGeneric::transform_real_to_unit_cell
---

diff --git a/source/fe/mapping_q_generic.cc b/source/fe/mapping_q_generic.cc
index b4e5d22f8b..959445efec 100644
--- a/source/fe/mapping_q_generic.cc
+++ b/source/fe/mapping_q_generic.cc
@@ -2534,7 +2534,7 @@ MappingQGeneric<dim, spacedim>::transform_real_to_unit_cell(
 {
   // Use an exact formula if one is available. this is only the case
   // for Q1 mappings in 1d, and in 2d if dim==spacedim
-  if ((polynomial_degree == 1) &&
+  if (this->preserves_vertex_locations() && (polynomial_degree == 1) &&
       ((dim == 1) || ((dim == 2) && (dim == spacedim))))
     {
       // The dimension-dependent algorithms are much faster (about 25-45x in