Fix crash on every Glade() construction that blocked GUI startup

gramps/gui/glade.py

@@ -61,12 +61,12 @@ class Glade(Gtk.Builder):
 
     def __setattr__(self, name, value):
         if not hasattr(self, name) and name not in [
-            "__toplevel",
-            "__filename",
-            "__dirname",
+            "_Glade__toplevel",
+            "_Glade__filename",
+            "_Glade__dirname",
         ]:
             raise AttributeError(f"Ad-hoc attribute {name} is not permitted.")
-        super().__setattr__(self, name, value)
+        super().__setattr__(name, value)
 
     def __init__(self, filename=None, dirname=None, toplevel=None, also_load=[]):
         """

gramps/gui/test/glade_test.py

@@ -0,0 +1,89 @@
+"""Unittest for glade.py
+
+Regression test for the ``Glade.__setattr__`` guard introduced by
+f8c1fc0f50 ("Don't use slots on GObject-derived classes."), which made every
+``Glade()`` construction abort GUI startup (testbed #1):
+
+  1. The guard whitelisted the *unmangled* names ``__toplevel``/``__filename``/
+     ``__dirname``, but ``__init__`` assigns ``self.__dirname`` etc., which
+     Python name-mangles to ``_Glade__dirname`` -- so the guard rejected the
+     class's own assignments with ``AttributeError`` at the very first
+     ``self.__dirname, self.__filename = os.path.split(path)`` line.
+  2. ``super().__setattr__(self, name, value)`` passed ``self`` twice to an
+     already-bound ``super()`` method, raising ``TypeError`` once the guard was
+     satisfied.
+
+The test drives the *real* ``Glade.__init__`` path end-to-end -- it loads an
+actual ``.glade`` file through ``Gtk.Builder`` -- so the fix is exercised the
+way GUI startup uses it, not via a synthetic ``__setattr__`` bypass. To stay
+runnable under the headless C4 unittest runner (no display / D-Bus / AT-SPI),
+the loaded glade file contains a single *non-widget* toplevel (a
+``GtkListStore``): building it needs the GObject type system but no display.
+"""
+
+import os
+import tempfile
+import unittest
+
+from gramps.gui.glade import Glade
+
+# A minimal, display-free glade file: one non-widget toplevel object so that
+# Gtk.Builder can build it on a headless box (no realised widgets).
+_GLADE_LISTSTORE = """<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkListStore" id="test_store">
+    <columns>
+      <column type="gchararray"/>
+    </columns>
+  </object>
+</interface>
+"""
+
+
+class GladeConstructionTest(unittest.TestCase):
+    """Constructing a Glade must run __init__'s guarded assignments cleanly."""
+
+    def setUp(self):
+        self._tmpdir = tempfile.TemporaryDirectory()
+        self._dirname = self._tmpdir.name
+        self._filename = "regtest.glade"
+        with open(
+            os.path.join(self._dirname, self._filename), "w", encoding="utf-8"
+        ) as handle:
+            handle.write(_GLADE_LISTSTORE)
+
+    def tearDown(self):
+        self._tmpdir.cleanup()
+
+    def test_real_construction_succeeds(self):
+        # The real __init__ path. Pre-fix this aborts with AttributeError
+        # ("Ad-hoc attribute _Glade__dirname is not permitted.") at the first
+        # `self.__dirname, self.__filename = os.path.split(path)` assignment,
+        # or TypeError from the doubled `self` once the whitelist is corrected.
+        # Post-fix it loads the file and assigns all three mangled privates.
+        glade = Glade(
+            filename=self._filename,
+            dirname=self._dirname,
+            toplevel="test_store",
+        )
+        # The three private attributes __init__ assigns via the guarded
+        # __setattr__, exposed through the public @property getters.
+        self.assertEqual(glade.dirname, self._dirname)
+        self.assertEqual(glade.filename, self._filename)
+        self.assertIsNotNone(glade.toplevel)
+        self.assertIsNotNone(glade.get_object("test_store"))
+
+    def test_adhoc_attr_still_rejected(self):
+        # The guard's purpose -- rejecting genuinely unexpected attributes --
+        # must be preserved by the fix.
+        glade = Glade(
+            filename=self._filename,
+            dirname=self._dirname,
+            toplevel="test_store",
+        )
+        with self.assertRaises(AttributeError):
+            glade.some_unexpected_attr = 1
+
+
+if __name__ == "__main__":
+    unittest.main()

po/POTFILES.skip

@@ -439,6 +439,7 @@ gramps/gui/selectors/selectorfactory.py
 # gui.test package
 #
 gramps/gui/test/display_test.py
+gramps/gui/test/glade_test.py
 gramps/gui/test/user_test.py
 #
 # gui/views - the GUI views package