https://github.com/mate-desktop/mate-settings-daemon/commit/42e91f2805c508317b4d26166cb3db332dd313e8.patch
From: Colomban Wendling <cwendling@hypra.fr>
Date: Tue, 27 Jun 2023 12:21:16 +0200
Subject: [PATCH] a11y-keyboard-atspi: Fix memory leak

Fix fairly large memory leak when beeping on keys while caps lock is
enabled.  The libatspi2 docs and API were quite misleading, so I
overlooked the fact the event parameter should be freed in the
callback.

This changes the constness of the callback argument, which is new in
libatspi2 2.40 -- yet the actual behavior didn't change, only the
qualifier was removed, see [1].
This might however bring up a compiler warning when building against
libatspi2 < 2.40;  but on the other hand it fixed build with
clang >= 16, see #399.  As it is unlikely to build with clang >= 16
and libatspi2 < 2.40, I think it's a good compromise.

[1] https://gitlab.gnome.org/GNOME/at-spi2-core/-/commit/7dfb0b7fc2d1710ef7fad54f910fa4c6a5e3af17
--- a/plugins/a11y-keyboard/msd-a11y-keyboard-atspi.c
+++ b/plugins/a11y-keyboard/msd-a11y-keyboard-atspi.c
@@ -55,16 +55,16 @@ msd_a11y_keyboard_atspi_class_init (MsdA11yKeyboardAtspiClass *klass)
 }
 
 static gboolean
-on_key_press_event (const AtspiDeviceEvent *event,
-                    void                   *user_data G_GNUC_UNUSED)
+on_key_press_event (AtspiDeviceEvent *event,
+                    void             *user_data G_GNUC_UNUSED)
 {
         /* don't ring on capslock itself, that's taken care of by togglekeys
          * if the user want it. */
-        if (event->id == GDK_KEY_Caps_Lock)
-                return FALSE;
-
-        gdk_display_beep (gdk_display_get_default ());
+        if (event->id != GDK_KEY_Caps_Lock)
+                gdk_display_beep (gdk_display_get_default ());
 
+        /* cast the possible erroneous const away with atspi < 2.40 */
+        g_boxed_free (ATSPI_TYPE_DEVICE_EVENT, (gpointer) event);
         return FALSE;
 }