make sure two maps connecting lower-d and higher-d elements are built…

… in recovery mode idaholab#27696

framework/include/mesh/MooseMesh.h

@@ -1797,6 +1797,9 @@ class MooseMesh : public MooseObject, public Restartable, public PerfGraphInterf
   /// Build extra data for faster access to the information of extra element integers
   void buildElemIDInfo();
 
+  /// Build two maps to connect lower-d elements with interior parent elements
+  void connectLowerDMesh();
+
   /// Build lower-d mesh for all sides
   void buildLowerDMesh();
 

framework/src/mesh/MooseMesh.C

@@ -523,6 +523,29 @@ MooseMesh::update()
   _finite_volume_info_dirty = true;
 }
 
+void
+MooseMesh::connectLowerDMesh()
+{
+  for (const auto & elem : getMesh().active_element_ptr_range())
+  {
+    const auto parent = elem->interior_parent();
+    if (!parent)
+      continue;
+
+    auto side = parent->which_side_am_i(elem);
+
+    // For some grid sequencing tests: side == libMesh::invalid_uint
+    if (side != libMesh::invalid_uint)
+    {
+      auto pair = std::make_pair(parent, side);
+      auto link = std::make_pair(pair, elem);
+      auto ilink = std::make_pair(elem, side);
+      _lower_d_elem_to_higher_d_elem_side.insert(ilink);
+      _higher_d_elem_side_to_lower_d_elem.insert(link);
+    }
+  }
+}
+
 void
 MooseMesh::buildLowerDMesh()
 {
@@ -2677,6 +2700,9 @@ MooseMesh::init()
 
     getMesh().allow_renumbering(allow_renumbering_later);
     getMesh().skip_partitioning(skip_partitioning_later);
+
+    if (getParam<bool>("build_all_side_lowerd_mesh"))
+      connectLowerDMesh();
   }
   else // Normally just build the mesh
   {