From a016f6e5c899d328f8dec8c507fa8307a5fef742 Mon Sep 17 00:00:00 2001
From: Dion Moult <dion@thinkmoult.com>
Date: Sun, 5 Oct 2025 18:44:14 +1100
Subject: [PATCH] Fix #7186. Support upgrading IFC2X3
 IfcExtendedMaterialProperties to IFC4

---
 .../ifcopenshell/util/attribute_4_to_2x3.json   |  2 +-
 .../ifcopenshell/util/class_2x3_to_4.json       |  1 +
 .../test/util/test_schema.py                    | 17 +++++++++++++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/ifcopenshell-python/ifcopenshell/util/attribute_4_to_2x3.json b/src/ifcopenshell-python/ifcopenshell/util/attribute_4_to_2x3.json
index 5cf025688c..6de4567868 100644
--- a/src/ifcopenshell-python/ifcopenshell/util/attribute_4_to_2x3.json
+++ b/src/ifcopenshell-python/ifcopenshell/util/attribute_4_to_2x3.json
@@ -173,7 +173,7 @@
         "Identification": "ItemReference"
     },
     "IfcMaterialProperties": {
-        "Name": "Material"
+        "Properties": "ExtendedProperties"
     },
     "IfcBlobTexture": {
         "Mode": "TextureType",
diff --git a/src/ifcopenshell-python/ifcopenshell/util/class_2x3_to_4.json b/src/ifcopenshell-python/ifcopenshell/util/class_2x3_to_4.json
index e3b6cba1df..3addf1516f 100644
--- a/src/ifcopenshell-python/ifcopenshell/util/class_2x3_to_4.json
+++ b/src/ifcopenshell-python/ifcopenshell/util/class_2x3_to_4.json
@@ -5,4 +5,5 @@
     , "IfcAnnotationSurfaceOccurrence": "IfcStyledItem"
     , "IfcAnnotationSymbolOccurrence": "IfcStyledItem"
     , "IfcAnnotationTextOccurrence": "IfcStyledItem"
+    , "IfcExtendedMaterialProperties": "IfcMaterialProperties"
 }
diff --git a/src/ifcopenshell-python/test/util/test_schema.py b/src/ifcopenshell-python/test/util/test_schema.py
index 071ffb8cea..aa24de6360 100644
--- a/src/ifcopenshell-python/test/util/test_schema.py
+++ b/src/ifcopenshell-python/test/util/test_schema.py
@@ -118,3 +118,20 @@ END-ISO-10303-21;
         assert qt_float_count_measure_ifc4x3.is_a("IfcQuantityNumber")
         assert isinstance(qt_float_count_measure_ifc4x3[3], float)
         assert qt_float_count_measure_ifc4x3[3] == 723.0
+
+    def test_migrate_extended_material_properties_ifc2x3_ifc4(self):
+        ifc2x3_file = ifcopenshell.api.project.create_file(version="IFC2X3")
+        material = ifc2x3_file.createIfcMaterial(Name="Material")
+        props = [ifc2x3_file.createIfcPropertySingleValue(Name="Foo")]
+        original_element = ifc2x3_file.createIfcExtendedMaterialProperties(Material=material, ExtendedProperties=props)
+        ifc4_file = ifcopenshell.api.project.create_file()
+
+        migrator = subject.Migrator()
+        for element in ifc2x3_file:
+            migrator.migrate(element, ifc4_file)
+
+        new_element = ifc4_file.by_type("IfcMaterialProperties")[0]
+        assert new_element.Material.is_a("IfcMaterial")
+        assert new_element.Material.Name == "Material"
+        assert new_element.Properties[0].is_a("IfcPropertySingleValue")
+        assert new_element.Properties[0].Name == "Foo"