Fix Migrate not migrating ifc file header #5903

src/ifcopenshell-python/ifcopenshell/util/schema.py

@@ -312,6 +312,7 @@ class Migrator:
         }
 
     def preprocess(self, old_file: ifcopenshell.file, new_file: ifcopenshell.file) -> None:
+        new_file.assign_header_from(old_file)
         to_delete = set()
 
         if old_file.schema == "IFC2X3" and new_file.schema == "IFC4":

src/ifcpatch/test/test_Migrate.py

@@ -0,0 +1,29 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2022 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcpatch
+import ifcopenshell
+import test.bootstrap
+
+
+class TestMigrate(test.bootstrap.IFC4):
+    def test_migrate_header(self):
+        old_file = self.file
+        old_file.header.file_name.name = "test"
+        new_file = ifcpatch.execute({"file": old_file, "recipe": "Migrate", "arguments": ["IFC4"]})
+        assert new_file.header.file_name.name == "test"