Improve operator --

diff --git a/include/deal.II/grid/tria_accessor.templates.h b/include/deal.II/grid/tria_accessor.templates.h
index 4e68cf6f98c1dfc7e6121240173419cf9a257ac7..031e86d7702b03d62dda792d3750ab0f52f94a7c 100644 (file)
--- a/include/deal.II/grid/tria_accessor.templates.h
+++ b/include/deal.II/grid/tria_accessor.templates.h
@@ -2240,10 +2240,11 @@ inline
 void
 TriaAccessor<0, dim, spacedim>::operator -- ()
 {
-  if (global_vertex_index!=numbers::invalid_unsigned_int)
+  if (global_vertex_index != numbers::invalid_unsigned_int)
     {
-      --global_vertex_index;
-      if (global_vertex_index==static_cast<unsigned int>(-1))
+      if (global_vertex_index != 0)
+        --global_vertex_index;
+      else
         global_vertex_index = numbers::invalid_unsigned_int;
     }
 }