Update n_elem/n_nodes caches more frequently

This seems to fix the regression with Gmsh->ParallelMesh reads

src/mesh/parallel_mesh.C

@@ -450,6 +450,12 @@ Elem* ParallelMesh::insert_elem (Elem* e)
   if (_elements[e->id()])
     this->delete_elem(_elements[e->id()]);
 
+  // Try to make the cached elem data more accurate
+  processor_id_type elem_procid = e->processor_id();
+  if (elem_procid == this->processor_id() ||
+      elem_procid == DofObject::invalid_processor_id)
+    _n_elem++;
+
   _elements[e->id()] = e;
 
   return e;
@@ -461,6 +467,12 @@ void ParallelMesh::delete_elem(Elem* e)
 {
   libmesh_assert (e);
 
+  // Try to make the cached elem data more accurate
+  processor_id_type elem_procid = e->processor_id();
+  if (elem_procid == this->processor_id() ||
+      elem_procid == DofObject::invalid_processor_id)
+    _n_elem--;
+
   // Delete the element from the BoundaryInfo object
   this->get_boundary_info().remove(e);
 
@@ -620,6 +632,12 @@ void ParallelMesh::delete_node(Node* n)
   libmesh_assert(n);
   libmesh_assert(_nodes[n->id()]);
 
+  // Try to make the cached elem data more accurate
+  processor_id_type node_procid = n->processor_id();
+  if (node_procid == this->processor_id() ||
+      node_procid == DofObject::invalid_processor_id)
+    _n_nodes--;
+
   // Delete the node from the BoundaryInfo object
   this->get_boundary_info().remove(n);