Fix #6760

src/bonsai/bonsai/bim/module/project/operator.py

@@ -1538,7 +1538,8 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
     bl_description = "Save active IFC file by the provided filepath."
     bl_options = {"REGISTER", "UNDO"}
     filename_ext = ".ifc"
-    filter_glob: bpy.props.StringProperty(default="*.ifc;*.ifczip;*.ifcxml;*.ifcjson", options={"HIDDEN"})
+    supported_filexts = (".ifc", ".ifczip", ".ifcjson")
+    filter_glob: bpy.props.StringProperty(default=",".join(f"*{ext}" for ext in supported_filexts), options={"HIDDEN"})
     json_version: bpy.props.EnumProperty(items=[("4", "4", ""), ("5a", "5a", "")], name="IFC JSON Version")
     json_compact: bpy.props.BoolProperty(name="Export Compact IFCJSON", default=False)
     should_save_as: bpy.props.BoolProperty(name="Should Save As", default=False, options={"HIDDEN"})
@@ -1557,7 +1558,7 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
 
         layout.separator()
         layout.label(text="Supported formats for export:")
-        layout.label(text=".ifc, .ifczip, .ifcjson")
+        layout.label(text=",".join(self.supported_filexts))
 
     def invoke(self, context, event):
         if not tool.Ifc.get():
@@ -1572,6 +1573,14 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
 
         return ExportHelper.invoke(self, context, event)
 
+    def check(self, context):
+        # ExportHelper is automatically adjusting suffix to `filename_ext`.
+        filepath = Path(self.filepath)
+        suffix = filepath.suffix.lower()
+        if suffix != self.filename_ext and suffix in self.supported_filexts:
+            self.filename_ext = suffix
+        return ExportHelper.check(self, context)
+
     def execute(self, context):
         project_props = tool.Project.get_project_props()
         project_props.use_relative_project_path = self.use_relative_path