cd completer considers bookmarks if no other matches are available

IPython/Extensions/ipy_completers.py

@@ -335,6 +335,12 b' def cd_completer(self, event):'
     if not found:
         if os.path.isdir(relpath):
             return [relpath]
+        
+        bks = self.db.get('bookmarks',{}).keys()
+        bkmatches = [s for s in bks if s.startswith(event.symbol)]
+        if bkmatches:
+            return bkmatches
+        
         raise IPython.ipapi.TryNext