From ad16ad2d6a7e7e4408ec8e7e45a996de1542e6a1 Mon Sep 17 00:00:00 2001
From: Peter Munch <peterrmuench@gmail.com>
Date: Sun, 24 Nov 2024 21:38:08 +0100
Subject: [PATCH] Add assert

---
 source/grid/tria.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/source/grid/tria.cc b/source/grid/tria.cc
index 4a2d365c9c..02305f7aee 100644
--- a/source/grid/tria.cc
+++ b/source/grid/tria.cc
@@ -12857,6 +12857,9 @@ template <int dim, int spacedim>
 DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
 void Triangulation<dim, spacedim>::refine_global(const unsigned int times)
 {
+  Assert(n_cells() > 0,
+         ExcMessage("Error: An empty Triangulation can not be refined."));
+
   for (unsigned int i = 0; i < times; ++i)
     {
       set_all_refine_flags();
-- 
2.39.5