Guard HasShapeAspects access on IFC2X3 representation iteration

IFC2X3 representations have no HasShapeAspects inverse; opening the
Geometry & Materials subpanel on an IFC2X3 object raised AttributeError
and left the items list empty. Wrap the access with a getattr default
so pre-IFC4 schemas return an empty iterable, and pin the contract with
an AST forward-compat guard that scans bim/, tool/, and core/ for any
future direct .HasShapeAspects access.

Closes #8157

Generated with the assistance of an AI coding tool.

src/bonsai/bonsai/bim/module/geometry/operator.py

@@ -3170,7 +3170,7 @@ class EnableEditingRepresentationItems(bpy.types.Operator, tool.Ifc.Operator):
                 product_reps = element.RepresentationMaps
             item_aspect = {}
             for product_rep in product_reps:
-                for aspect in product_rep.HasShapeAspects:
+                for aspect in getattr(product_rep, "HasShapeAspects", ()):
                     for aspect_rep in aspect.ShapeRepresentations:
                         if aspect_rep.ContextOfItems != representation.ContextOfItems:
                             continue

src/bonsai/test/bim/module/geometry/__init__.py

@@ -0,0 +1,17 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.

src/bonsai/test/bim/module/geometry/test_shape_aspects_forward_compat.py

@@ -0,0 +1,61 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2026
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was generated with the assistance of an AI coding tool.
+
+"""Forward-compat AST contract: ``HasShapeAspects`` is an IFC4+ inverse;
+direct attribute access raises ``AttributeError`` on pre-IFC4 entity
+instances. Production code must read it through ``getattr`` so the
+absence in earlier schemas degrades to an empty iterable."""
+
+import ast
+from pathlib import Path
+
+import pytest
+
+pytestmark = pytest.mark.geometry
+
+
+BONSAI_ROOT = Path(__file__).parent.parent.parent.parent.parent / "bonsai"
+PRODUCTION_DIRS = (BONSAI_ROOT / "bim", BONSAI_ROOT / "tool", BONSAI_ROOT / "core")
+
+ATTR_NAME = "HasShapeAspects"
+
+
+def _iter_production_sources():
+    for root in PRODUCTION_DIRS:
+        yield from root.rglob("*.py")
+
+
+def test_has_shape_aspects_access_uses_getattr_guard():
+    """Every read of ``HasShapeAspects`` in production code must go through
+    ``getattr(<expr>, "HasShapeAspects", <default>)`` so files using
+    schemas that omit the inverse return the default instead of raising."""
+    offenders = []
+    for source in _iter_production_sources():
+        tree = ast.parse(source.read_text(encoding="utf-8"))
+        for node in ast.walk(tree):
+            if isinstance(node, ast.Attribute) and node.attr == ATTR_NAME:
+                offenders.append(f"{source.relative_to(BONSAI_ROOT.parent)}:{node.lineno}")
+    if offenders:
+        joined = "\n  ".join(sorted(offenders))
+        pytest.fail(
+            f"Direct .{ATTR_NAME} attribute access in production code:\n  {joined}\n"
+            f"Wrap with getattr(<expr>, '{ATTR_NAME}', ()) so pre-IFC4 schemas "
+            f"do not raise AttributeError."
+        )