From 3bf248f04c180c8095e27489e741dee6377b5e9b Mon Sep 17 00:00:00 2001
From: goran-w <44604769+goran-w@users.noreply.github.com>
Date: Fri, 21 Dec 2018 08:59:13 +0100
Subject: [PATCH 1/2] Update File_medit.h

---
 Mesh_3/include/CGAL/IO/File_medit.h | 33 +++++++++++++++--------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/Mesh_3/include/CGAL/IO/File_medit.h b/Mesh_3/include/CGAL/IO/File_medit.h
index 8b12c81e1c4..84af6a8f9a3 100644
--- a/Mesh_3/include/CGAL/IO/File_medit.h
+++ b/Mesh_3/include/CGAL/IO/File_medit.h
@@ -815,27 +815,28 @@ output_to_medit(std::ostream& os,
        fit != c3t3.facets_in_complex_end();
        ++fit)
   {
-    for (int i=0; i<4; i++)
-    {
-      if (i != fit->second)
-      {
-        const Vertex_handle& vh = (*fit).first->vertex(i);
-        os << V[vh] << ' ';
-      }
-    }
+    C3T3::Facet f = (*fit);
+    
+    // Apply priority among subdomains, to get consistent facet orientation per subdomain-pair interface.
+    if (f.first->subdomain_index() < f.first->neighbor(f.second)->subdomain_index())
+      f = tr.mirror_facet(f);
+    
+    // Get facet vertices in CCW order.
+    Vertex_handle vh1 = f.first->vertex((f.second + 1) % 4);
+    Vertex_handle vh2 = f.first->vertex((f.second + 2) % 4);
+    Vertex_handle vh3 = f.first->vertex((f.second + 3) % 4);
+    
+    // Facet orientation also depends on parity.
+    if (f.second % 2 != 0)
+      std::swap(vh2, vh3);
+    
+    os << V[vh1] << ' ' << V[vh2] << ' ' << V[vh3] << ' '; 
     os << get(facet_pmap, *fit) << '\n';
     
     // Print triangle again if needed
     if ( print_each_facet_twice )
     {
-      for (int i=0; i<4; i++)
-      {
-        if (i != fit->second)
-        {
-          const Vertex_handle& vh = (*fit).first->vertex(i);
-          os << V[vh] << ' ';
-        }
-      }
+      os << V[vh1] << ' ' << V[vh2] << ' ' << V[vh3] << ' '; 
       os << get(facet_twice_pmap, *fit) << '\n';
     }
   }

From 509594f21d36d5e3d8c1547ec00807d7605b5957 Mon Sep 17 00:00:00 2001
From: goran-w <44604769+goran-w@users.noreply.github.com>
Date: Fri, 21 Dec 2018 11:46:04 +0100
Subject: [PATCH 2/2] Added missing typename qualifier.

My bad. Visual Studio 2017 compiler did not complain about this.
---
 Mesh_3/include/CGAL/IO/File_medit.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Mesh_3/include/CGAL/IO/File_medit.h b/Mesh_3/include/CGAL/IO/File_medit.h
index 84af6a8f9a3..656a6b5db98 100644
--- a/Mesh_3/include/CGAL/IO/File_medit.h
+++ b/Mesh_3/include/CGAL/IO/File_medit.h
@@ -815,7 +815,7 @@ output_to_medit(std::ostream& os,
        fit != c3t3.facets_in_complex_end();
        ++fit)
   {
-    C3T3::Facet f = (*fit);
+    typename C3T3::Facet f = (*fit);
     
     // Apply priority among subdomains, to get consistent facet orientation per subdomain-pair interface.
     if (f.first->subdomain_index() < f.first->neighbor(f.second)->subdomain_index())