Fix keymap editing not tagging dirty

Partial fix for T65629

release/scripts/startup/bl_operators/userpref.py

@@ -286,6 +286,7 @@ class PREFERENCES_OT_keymap_restore(Operator):
             km = context.keymap
             km.restore_to_default()
 
+        context.preferences.is_dirty = True
         return {'FINISHED'}
 
 
@@ -333,6 +334,7 @@ class PREFERENCES_OT_keyitem_add(Operator):
             km.show_expanded_items = True
             km.show_expanded_children = True
 
+        context.preferences.is_dirty = True
         return {'FINISHED'}
 
 
@@ -354,6 +356,8 @@ class PREFERENCES_OT_keyitem_remove(Operator):
         km = context.keymap
         kmi = km.keymap_items.from_id(self.item_id)
         km.keymap_items.remove(kmi)
+
+        context.preferences.is_dirty = True
         return {'FINISHED'}
 
 

source/blender/makesrna/intern/rna_userdef.c

@@ -5808,8 +5808,8 @@ void RNA_def_userdef(BlenderRNA *brna)
 
   prop = RNA_def_property(srna, "is_dirty", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_boolean_sdna(prop, NULL, "runtime.is_dirty", 0);
-  RNA_def_property_clear_flag(prop, PROP_EDITABLE);
   RNA_def_property_ui_text(prop, "Dirty", "Preferences have changed");
+  RNA_def_property_update(prop, 0, "rna_userdef_ui_update");
 
   rna_def_userdef_view(brna);
   rna_def_userdef_edit(brna);