BIM: Fixed missing object creation in IFC document conversion (#17093)

* BIM: Fixed missing object creation in IFC document conversion - fixes #17031

* BIM: fixed deleting of non-existing objects - fixes #17032

src/Mod/BIM/importers/exportIFC.py

@@ -1106,22 +1106,22 @@ def export(exportList, filename, colors=None, preferences=None):
                 None,
                 None
             )]
-        if buildings and (not sites):
-            ifcfile.createIfcRelAggregates(
-                ifcopenshell.guid.new(),
-                history,
-                'ProjectLink',
-                '',
-                project,buildings
-            )
-        if floors and buildings:
-            ifcfile.createIfcRelAggregates(
-                ifcopenshell.guid.new(),
-                history,
-                'BuildingLink',
-                '',
-                buildings[0],floors
-            )
+    if buildings and (not sites):
+        ifcfile.createIfcRelAggregates(
+            ifcopenshell.guid.new(),
+            history,
+            'ProjectLink',
+            '',
+            project,buildings
+        )
+    if floors and buildings:
+        ifcfile.createIfcRelAggregates(
+            ifcopenshell.guid.new(),
+            history,
+            'BuildingLink',
+            '',
+            buildings[0],floors
+        )
     if sites and buildings:
         ifcfile.createIfcRelAggregates(
             ifcopenshell.guid.new(),

src/Mod/BIM/nativeifc/ifc_status.py

@@ -193,6 +193,7 @@ def lock_document():
     doc = FreeCAD.ActiveDocument
     products = []
     spatial = []
+    ifcfile = None
     if "IfcFilePath" not in doc.PropertiesList:
         # this is not a locked document
         projects = [o for o in doc.Objects if getattr(o, "Class", None) == "IfcProject"]
@@ -249,7 +250,8 @@ def lock_document():
             prefs, context = ifc_tools.get_export_preferences(ifcfile)
             exportIFC.export(objs, ifcfile, preferences=prefs)
             for n in [o.Name for o in doc.Objects]:
-                doc.removeObject(n)
+                if doc.getObject(n):
+                    doc.removeObject(n)
             ifc_tools.create_children(doc, ifcfile, recursive=True)
             doc.Modified = True
             doc.commitTransaction()
@@ -260,6 +262,18 @@ def lock_document():
             ifc_tools.convert_document(doc)
             doc.commitTransaction()
             doc.recompute()
+        # reveal file contents if needed
+        if "IfcFilePath" in doc.PropertiesList:
+            create = True
+            for o in doc.Objects:
+                # scan for site or building
+                if getattr(o, "IfcClass", "") in ("IfcSite", "IfcBuilding"):
+                    create = False
+                    break
+            if create:
+                if not ifcfile:
+                    ifcfile = doc.Proxy.ifcfile
+                ifc_tools.create_children(doc, recursive=False)
 
 
 def find_toplevel(objs):