From 04d64de6d008f76e4efbdd821117d6d3f1873438 Mon Sep 17 00:00:00 2001
From: Dion Moult <dion@thinkmoult.com>
Date: Tue, 21 Sep 2021 16:56:28 +1000
Subject: [PATCH] Fix bug where you could add an opening twice to the same
 element.

---
 .../ifcopenshell/api/void/add_opening.py      |  7 +++++
 .../test/api/void/test_add_opening.py         | 27 +++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 src/ifcopenshell-python/test/api/void/test_add_opening.py

diff --git a/src/ifcopenshell-python/ifcopenshell/api/void/add_opening.py b/src/ifcopenshell-python/ifcopenshell/api/void/add_opening.py
index af97c931a7..878dfa8f46 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/void/add_opening.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/void/add_opening.py
@@ -10,6 +10,13 @@ class Usecase:
             self.settings[key] = value
 
     def execute(self):
+        voids_elements = self.settings["opening"].VoidsElements
+
+        if voids_elements:
+            if voids_elements[0].RelatingBuildingElement == self.settings["element"]:
+                return
+            self.file.remove(voids_elements[0])
+
         self.file.create_entity(
             "IfcRelVoidsElement",
             **{
diff --git a/src/ifcopenshell-python/test/api/void/test_add_opening.py b/src/ifcopenshell-python/test/api/void/test_add_opening.py
new file mode 100644
index 0000000000..69013ee552
--- /dev/null
+++ b/src/ifcopenshell-python/test/api/void/test_add_opening.py
@@ -0,0 +1,27 @@
+import test.bootstrap
+import ifcopenshell.api
+
+
+class TestAddOpening(test.bootstrap.IFC4):
+    def test_adding_an_opening(self):
+        wall = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        opening = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcOpeningElement")
+        ifcopenshell.api.run("void.add_opening", self.file, opening=opening, element=wall)
+        assert wall.HasOpenings[0].RelatedOpeningElement == opening
+
+    def test_adding_an_opening_twice(self):
+        wall = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        opening = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcOpeningElement")
+        ifcopenshell.api.run("void.add_opening", self.file, opening=opening, element=wall)
+        ifcopenshell.api.run("void.add_opening", self.file, opening=opening, element=wall)
+        assert wall.HasOpenings[0].RelatedOpeningElement == opening
+        assert len(wall.HasOpenings) == 1
+
+    def test_adding_an_opening_which_is_already_voiding_another_element(self):
+        slab = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcSlab")
+        wall = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        opening = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcOpeningElement")
+        ifcopenshell.api.run("void.add_opening", self.file, opening=opening, element=slab)
+        ifcopenshell.api.run("void.add_opening", self.file, opening=opening, element=wall)
+        assert not slab.HasOpenings
+        assert wall.HasOpenings[0].RelatedOpeningElement == opening