Prevent redundant traversal of parser aliases.

Author: kmvanbrunt

cmd2/cmd2.py

@@ -1034,7 +1034,14 @@ def check_parser_uninstallable(parser: Cmd2ArgumentParser) -> None:
                 # No subcommands to check
                 return
 
+            # Prevent redundant traversal of parser aliases
+            checked_parsers: set[Cmd2ArgumentParser] = set()
+
             for subparser in subparsers_action.choices.values():
+                if subparser in checked_parsers:
+                    continue
+                checked_parsers.add(subparser)
+
                 attached_cmdset_id = getattr(subparser, constants.PARSER_ATTR_COMMANDSET_ID, None)
                 if attached_cmdset_id is not None and attached_cmdset_id != cmdset_id:
                     raise CommandSetRegistrationError(

examples/scripts/save_help_text.py

@@ -19,8 +19,15 @@ def get_sub_commands(parser: Cmd2ArgumentParser) -> list[str]:
         # No subcommands
         return []
 
+    # Prevent redundant traversal of parser aliases
+    checked_parsers: set[Cmd2ArgumentParser] = set()
+
     sub_cmds = []
     for subcmd, subcmd_parser in subparsers_action.choices.items():
+        if subcmd_parser in checked_parsers:
+            continue
+        checked_parsers.add(subcmd_parser)
+
         sub_cmds.append(subcmd)
 
         # Look for nested subcommands