Only write to gui.json once during shutdown

src/calibre/gui2/ui.py

@@ -702,6 +702,7 @@ class Main(MainWindow, MainWindowMixin, DeviceMixin, EmailMixin, # {{{
         self.read_layout_settings()
 
     def write_settings(self):
+        with gprefs: # Only write to gprefs once
             config.set('main_window_geometry', self.saveGeometry())
             dynamic.set('sort_history', self.library_view.model().sort_history)
             self.save_layout_state()

src/calibre/utils/config.py

@@ -240,6 +240,7 @@ class XMLConfig(dict):
 
     def __init__(self, rel_path_to_cf_file):
         dict.__init__(self)
+        self.no_commit = False
         self.defaults = {}
         self.file_path = os.path.join(config_dir,
                 *(rel_path_to_cf_file.split('/')))
@@ -304,6 +305,7 @@ class XMLConfig(dict):
             self.commit()
 
     def commit(self):
+        if self.no_commit: return
         if hasattr(self, 'file_path') and self.file_path:
             dpath = os.path.dirname(self.file_path)
             if not os.path.exists(dpath):
@@ -314,6 +316,13 @@ class XMLConfig(dict):
                 f.truncate()
                 f.write(raw)
 
+    def __enter__(self):
+        self.no_commit = True
+
+    def __exit__(self, *args):
+        self.no_commit = False
+        self.commit()
+
 def to_json(obj):
     if isinstance(obj, bytearray):
         return {'__class__': 'bytearray',