You can now clear the active user for ownership history. See #1790.

src/blenderbim/test/bim/feature/owner.feature

@@ -233,3 +233,8 @@ Scenario: Set user
     And the variable "user" is "{ifc}.by_type('IfcPersonAndOrganization')[0].id()"
     And I press "bim.set_user(user={user})"
     Then nothing happens
+
+Scenario: Clear user
+    Given an empty IFC project
+    When I press "bim.clear_user(user={user})"
+    Then nothing happens

src/blenderbim/test/core/test_owner.py

@@ -219,3 +219,9 @@ class TestGetUser:
     def test_run(self, owner):
         owner.get_user().should_be_called().will_return("person_and_organisation")
         assert subject.get_user(owner) == "person_and_organisation"
+
+
+class TestClearUser:
+    def test_run(self, owner):
+        owner.clear_user().should_be_called()
+        subject.clear_user(owner)

src/blenderbim/test/tool/test_owner.py

@@ -45,6 +45,16 @@ class TestGetUser(test.bim.bootstrap.NewFile):
         user = tool.Ifc.get().by_type("IfcPersonAndOrganization")[0]
         assert subject.get_user() == user
 
+    def test_falling_back_to_any_available_user_ifc2x3(self):
+        assert subject.get_user() is None
+        ifc = ifcopenshell.file(schema="IFC2X3")
+        tool.Ifc.set(ifc)
+        user = ifc.createIfcPersonAndOrganization()
+        assert subject.get_user() == user
+        user2 = ifc.createIfcPersonAndOrganization()
+        subject.set_user(user2)
+        assert subject.get_user() == user2
+
 
 class TestClearUser(test.bim.bootstrap.NewFile):
     def test_run(self):