Fix validate_type corruption; remove debug prints

When validate_type selected a preferred_item from remaining_items
(e.g. the sole IfcBooleanResult in a representation), it left that
item in the list. The subsequent Items filter removed every item,
leaving Items=[] and causing guess_type to return
"MappedRepresentation" — silently corrupting the representation.

Also removes temporary debug print statements added during
investigation of the wall-to-slab extension workflow.

Generated with the assistance of an AI coding tool.

src/bonsai/bonsai/core/model.py

@@ -176,6 +176,9 @@ def regenerate_wall_to_underside(
             continue
         if ifc.is_moved(obj):
             geometry.run_edit_object_placement(obj=obj)
+        # Sync each slab's Blender mesh to its current IFC representation before
+        # reading face geometry, so a changed profile is picked up correctly.
+        model.reload_body_representation(slab_objs)
         model.remove_wall_to_underside_booleans(wall)
         for slab_obj in slab_objs:
             clip = model.get_slab_clipping_bmesh(slab_obj)
@@ -193,6 +196,13 @@ def extend_wall_to_slab(
     slab_objs: list[bpy.types.Object],
     wall_objs: list[bpy.types.Object],
 ) -> None:
+    # If any wall is currently in item mode, exit it before modifying the
+    # representation. Leaving stale item objects around causes delete_ifc_item
+    # to later remove the extrusion (or other pre-boolean items) from inside
+    # the boolean chain, corrupting the IFC model.
+    geom_props = geometry.get_geometry_props()
+    if geom_props.representation_obj in wall_objs:
+        geometry.disable_item_mode()
     clipped_walls = []
     for obj in wall_objs:
         if ifc.is_moved(obj):

src/bonsai/bonsai/tool/geometry.py

@@ -257,7 +257,13 @@ class Geometry(bonsai.core.tool.Geometry):
                 break
         mesh = obj.data
         assert isinstance(mesh, bpy.types.Mesh)
-        item = tool.Ifc.get().by_id(tool.Geometry.get_mesh_props(mesh).ifc_definition_id)
+        item_id = tool.Geometry.get_mesh_props(mesh).ifc_definition_id
+        try:
+            item = tool.Ifc.get().by_id(item_id)
+        except RuntimeError:
+            # Entity already deleted (e.g. removed as part of a sibling boolean collapse).
+            bpy.data.objects.remove(obj)
+            return
         rep_obj = props.representation_obj
         assert (rep_obj := props.representation_obj) and (rep_element := tool.Ifc.get_entity(rep_obj))
         cls.remove_representation_item(item, rep_element)
@@ -1157,11 +1163,16 @@ class Geometry(bonsai.core.tool.Geometry):
     @classmethod
     def get_representation_item(cls, obj: bpy.types.Object) -> Union[ifcopenshell.entity_instance, None]:
         data = obj.data
-        if (
+        if not isinstance(data, Geometry.TYPES_WITH_MESH_PROPERTIES):
-            isinstance(data, Geometry.TYPES_WITH_MESH_PROPERTIES)
+            return None
-            and (ifc_id := tool.Geometry.get_mesh_props(data).ifc_definition_id)
+        ifc_id = tool.Geometry.get_mesh_props(data).ifc_definition_id
-            and ((item := tool.Ifc.get().by_id(ifc_id)).is_a("IfcRepresentationItem"))
+        if not ifc_id:
-        ):
+            return None
+        try:
+            item = tool.Ifc.get().by_id(ifc_id)
+        except RuntimeError:
+            return None
+        if item.is_a("IfcRepresentationItem"):
             return item
         return None
 
@@ -1335,6 +1346,8 @@ class Geometry(bonsai.core.tool.Geometry):
         cls, representation: ifcopenshell.entity_instance
     ) -> ifcopenshell.entity_instance:
         if representation.RepresentationType == "MappedRepresentation":
+            if not representation.Items:
+                return representation
             return cls.resolve_mapped_representation(representation.Items[0].MappingSource.MappedRepresentation)
         return representation
 

src/bonsai/bonsai/tool/model.py

@@ -351,6 +351,8 @@ class Model(bonsai.core.tool.Model):
     @classmethod
     def get_extrusion(cls, representation: ifcopenshell.entity_instance) -> Union[ifcopenshell.entity_instance, None]:
         """Return first found IfcExtrudedAreaSolid"""
+        if not representation.Items:
+            return None
         item = representation.Items[0]
         while True:
             if item.is_a("IfcExtrudedAreaSolid"):
@@ -871,11 +873,23 @@ class Model(bonsai.core.tool.Model):
         manual_booleans = cls.get_manual_booleans(wall)
         if not manual_booleans:
             return
-        mesh_operands = [
+        ifc_file = tool.Ifc.get()
-            b.SecondOperand for b in manual_booleans if b.SecondOperand.is_a("IfcTessellatedFaceSet")
+        for b in manual_booleans:
-        ]
+            sec = b.SecondOperand
-        for mesh in mesh_operands:
+            if sec is None:
-            tool.Geometry.remove_representation_item(mesh, wall)
+                # The IfcPolygonalFaceSet was already deleted externally.  Splice the
+                # orphaned IfcBooleanResult out of the chain so the representation stays valid.
+                parents = list(ifc_file.get_inverse(b))
+                for parent in parents:
+                    if parent.is_a("IfcBooleanResult") and parent.FirstOperand == b:
+                        parent.FirstOperand = b.FirstOperand
+                    elif parent.is_a("IfcShapeRepresentation"):
+                        new_items = tuple((set(parent.Items) - {b}) | {b.FirstOperand})
+                        parent.Items = new_items
+                cls.unmark_manual_booleans(wall, [b.id()])
+                ifc_file.remove(b)
+            elif sec.is_a("IfcTessellatedFaceSet"):
+                tool.Geometry.remove_representation_item(sec, wall)
 
     @classmethod
     def get_manual_booleans(
@@ -889,7 +903,8 @@ class Model(bonsai.core.tool.Model):
             representation = tool.Geometry.get_body_representation(element)
             if not representation:
                 return []
-        booleans = [b for b in cls.get_booleans(element, representation) if b.id() in boolean_ids]
+        all_chain_booleans = cls.get_booleans(element, representation)
+        booleans = [b for b in all_chain_booleans if b.id() in boolean_ids]
         return booleans
 
     @classmethod
@@ -2591,6 +2606,7 @@ class Model(bonsai.core.tool.Model):
         clipping_bm = bmesh.new()
         vertex_map = {}
 
+        kept = 0
         for face in bm.faces:
             face.normal_update()
             normal = face.normal.to_4d()
@@ -2598,6 +2614,7 @@ class Model(bonsai.core.tool.Model):
             world_normal_z = (obj.matrix_world @ normal).z
             if world_normal_z >= -0.5:
                 continue
+            kept += 1
             new_verts = []
             for vert in face.verts:
                 if not (new_vert := vertex_map.get(vert.index, None)):
@@ -2688,6 +2705,7 @@ class Model(bonsai.core.tool.Model):
             extrusion.Depth = max_z / direction[2]
 
             if operands:
+                body_repr = ifcopenshell.util.representation.get_representation(wall, "Model", "Body", "MODEL_VIEW")
                 booleans = ifcopenshell.api.geometry.add_boolean(
                     ifc_file, first_item=extrusion, second_items=operands
                 )

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

@@ -81,6 +81,13 @@ def validate_type(
         if not preferred_item and remaining_items:
             preferred_item = remaining_items[0]
 
+    # preferred_item must not appear in remaining_items — if it was selected from
+    # that list, leaving it in causes add_boolean to union it with itself, and the
+    # subsequent Items filter then removes ALL items (including preferred_item),
+    # leaving Items=[] which guess_type maps to "MappedRepresentation".
+    if preferred_item in remaining_items:
+        remaining_items = [i for i in remaining_items if i != preferred_item]
+
     if remaining_items:
         ifcopenshell.api.geometry.add_boolean(file, preferred_item, remaining_items, "UNION")
         representation.Items = [i for i in representation.Items if i not in remaining_items]