Fix potential instability when assigning types and synchronising Blender geometry

src/ifcopenshell-python/ifcopenshell/api/geometry/data.py

@@ -14,11 +14,8 @@ class Data:
         cls.products[product_id] = []
         product = file.by_id(product_id)
         representations = []
-        if product.is_a("IfcProduct"):
-            if product.Representation:
-                representations = product.Representation.Representations
-            else:
-                representations = []
+        if product.is_a("IfcProduct") and product.Representation:
+            representations = product.Representation.Representations
         elif product.is_a("IfcTypeProduct"):
             representations = [rm.MappedRepresentation for rm in product.RepresentationMaps or []]
         for representation in representations:

src/ifcopenshell-python/ifcopenshell/api/type/assign_type.py

@@ -52,3 +52,30 @@ class Usecase:
                     "RelatingType": self.settings["relating_type"],
                 }
             )
+
+        self.map_representations()
+
+    def map_representations(self):
+        if not self.settings["relating_type"].RepresentationMaps:
+            return
+        representations = []
+        if self.settings["related_object"].Representation:
+            representations = self.settings["related_object"].Representation.Representations
+        for representation in representations:
+            # TODO: check if this is right? Surely this can be a single usecase?
+            ifcopenshell.api.run(
+                "geometry.unassign_representation",
+                self.file,
+                **{"product": self.settings["related_object"], "representation": representation}
+            )
+            ifcopenshell.api.run("geometry.remove_representation", self.file, **{"representation": representation})
+        for representation_map in self.settings["relating_type"].RepresentationMaps:
+            representation = representation_map.MappedRepresentation
+            result = ifcopenshell.api.run(
+                "geometry.map_representation", self.file, **{"representation": representation}
+            )
+            ifcopenshell.api.run(
+                "geometry.assign_representation",
+                self.file,
+                **{"product": self.settings["related_object"], "representation": result}
+            )