Fix bug where loading drawings didn't correctly link shared meshes (e.g. from a type of an annotation)

src/blenderbim/blenderbim/bim/import_ifc.py

@@ -1164,6 +1164,9 @@ class IfcImporter:
 
         return obj
 
+    def load_existing_meshes(self) -> None:
+        self.meshes.update({m.name: m for m in bpy.data.meshes})
+
     def get_representation_item_material_name(self, item):
         if not item.StyledByItem:
             return

src/blenderbim/blenderbim/tool/drawing.py

@@ -607,6 +607,7 @@ class Drawing(blenderbim.core.tool.Drawing):
         ifc_importer.file = tool.Ifc.get()
         ifc_importer.calculate_unit_scale()
         ifc_importer.process_context_filter()
+        ifc_importer.load_existing_meshes()
         ifc_importer.material_creator.load_existing_materials()
         ifc_importer.create_generic_elements(elements)
         for obj in ifc_importer.added_data.values():