[3.12] gh-58573: Fix conflicts between abbreviated long options in th…

…e parent parser and subparsers in argparse (GH-124631) (GH-124759)

Check for ambiguous options if the option is consumed, not when it is
parsed.
(cherry picked from commit 3f27153)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Lib/argparse.py

@@ -1971,11 +1971,11 @@ def _parse_known_args(self, arg_strings, namespace):
  # otherwise, add the arg to the arg strings
  # and note the index if it was an option
  else:
- option_tuple = self._parse_optional(arg_string)
- if option_tuple is None:
+ option_tuples = self._parse_optional(arg_string)
+ if option_tuples is None:
  pattern = 'A'
  else:
- option_string_indices[i] = option_tuple
+ option_string_indices[i] = option_tuples
  pattern = 'O'
  arg_string_pattern_parts.append(pattern)
 
@@ -2009,8 +2009,16 @@ def take_action(action, argument_strings, option_string=None):
  def consume_optional(start_index):
 
  # get the optional identified at this index
- option_tuple = option_string_indices[start_index]
- action, option_string, sep, explicit_arg = option_tuple
+ option_tuples = option_string_indices[start_index]
+ # if multiple actions match, the option string was ambiguous
+ if len(option_tuples) > 1:
+ options = ', '.join([option_string
+ for action, option_string, sep, explicit_arg in option_tuples])
+ args = {'option': arg_string, 'matches': options}
+ msg = _('ambiguous option: %(option)s could match %(matches)s')
+ raise ArgumentError(None, msg % args)
+
+ action, option_string, sep, explicit_arg = option_tuples[0]
 
  # identify additional optionals in the same arg string
  # (e.g. -xyz is the same as -x -y -z if no args are required)
@@ -2287,7 +2295,7 @@ def _parse_optional(self, arg_string):
  # if the option string is present in the parser, return the action
  if arg_string in self._option_string_actions:
  action = self._option_string_actions[arg_string]
- return action, arg_string, None, None
+ return [(action, arg_string, None, None)]
 
  # if it's just a single character, it was meant to be positional
  if len(arg_string) == 1:
@@ -2297,25 +2305,14 @@ def _parse_optional(self, arg_string):
  option_string, sep, explicit_arg = arg_string.partition('=')
  if sep and option_string in self._option_string_actions:
  action = self._option_string_actions[option_string]
- return action, option_string, sep, explicit_arg
+ return [(action, option_string, sep, explicit_arg)]
 
  # search through all possible prefixes of the option string
  # and all actions in the parser for possible interpretations
  option_tuples = self._get_option_tuples(arg_string)
 
- # if multiple actions match, the option string was ambiguous
- if len(option_tuples) > 1:
- options = ', '.join([option_string
- for action, option_string, sep, explicit_arg in option_tuples])
- args = {'option': arg_string, 'matches': options}
- msg = _('ambiguous option: %(option)s could match %(matches)s')
- raise ArgumentError(None, msg % args)
-
- # if exactly one action matched, this segmentation is good,
- # so return the parsed action
- elif len(option_tuples) == 1:
- option_tuple, = option_tuples
- return option_tuple
+ if option_tuples:
+ return option_tuples
 
  # if it was not found as an option, but it looks like a negative
  # number, it was meant to be positional
@@ -2330,7 +2327,7 @@ def _parse_optional(self, arg_string):
 
  # it was meant to be an optional but there is no such option
  # in this parser (though it might be a valid option in a subparser)
- return None, arg_string, None, None
+ return [(None, arg_string, None, None)]
 
  def _get_option_tuples(self, option_string):
  result = []
@@ -2380,43 +2377,40 @@ def _get_nargs_pattern(self, action):
  # in all examples below, we have to allow for '--' args
  # which are represented as '-' in the pattern
  nargs = action.nargs
+ # if this is an optional action, -- is not allowed
+ option = action.option_strings
 
  # the default (None) is assumed to be a single argument
  if nargs is None:
- nargs_pattern = '(-*A-*)'
+ nargs_pattern = '([A])' if option else '(-*A-*)'
 
  # allow zero or one arguments
  elif nargs == OPTIONAL:
- nargs_pattern = '(-*A?-*)'
+ nargs_pattern = '(A?)' if option else '(-*A?-*)'
 
  # allow zero or more arguments
  elif nargs == ZERO_OR_MORE:
- nargs_pattern = '(-*[A-]*)'
+ nargs_pattern = '(A*)' if option else '(-*[A-]*)'
 
  # allow one or more arguments
  elif nargs == ONE_OR_MORE:
- nargs_pattern = '(-*A[A-]*)'
+ nargs_pattern = '(A+)' if option else '(-*A[A-]*)'
 
  # allow any number of options or arguments
  elif nargs == REMAINDER:
- nargs_pattern = '([-AO]*)'
+ nargs_pattern = '([AO]*)' if option else '(.*)'
 
  # allow one argument followed by any number of options or arguments
  elif nargs == PARSER:
- nargs_pattern = '(-*A[-AO]*)'
+ nargs_pattern = '(A[AO]*)' if option else '(-*A[-AO]*)'
 
  # suppress action, like nargs=0
  elif nargs == SUPPRESS:
- nargs_pattern = '(-*-*)'
+ nargs_pattern = '()' if option else '(-*)'
 
  # all others should be integers
  else:
- nargs_pattern = '(-*%s-*)' % '-*'.join('A' * nargs)
-
- # if this is an optional action, -- is not allowed
- if action.option_strings:
- nargs_pattern = nargs_pattern.replace('-*', '')
- nargs_pattern = nargs_pattern.replace('-', '')
+ nargs_pattern = '([AO]{%d})' % nargs if option else '((?:-*A){%d}-*)' % nargs
 
  # return the pattern
  return nargs_pattern

Lib/test/test_argparse.py

@@ -2313,6 +2313,28 @@ class C:
  self.assertEqual(C.w, 7)
  self.assertEqual(C.x, 'b')
 
+ def test_abbreviation(self):
+ parser = ErrorRaisingArgumentParser()
+ parser.add_argument('--foodle')
+ parser.add_argument('--foonly')
+ subparsers = parser.add_subparsers()
+ parser1 = subparsers.add_parser('bar')
+ parser1.add_argument('--fo')
+ parser1.add_argument('--foonew')
+
+ self.assertEqual(parser.parse_args(['--food', 'baz', 'bar']),
+ NS(foodle='baz', foonly=None, fo=None, foonew=None))
+ self.assertEqual(parser.parse_args(['--foon', 'baz', 'bar']),
+ NS(foodle=None, foonly='baz', fo=None, foonew=None))
+ self.assertArgumentParserError(parser.parse_args, ['--fo', 'baz', 'bar'])
+ self.assertEqual(parser.parse_args(['bar', '--fo', 'baz']),
+ NS(foodle=None, foonly=None, fo='baz', foonew=None))
+ self.assertEqual(parser.parse_args(['bar', '--foo', 'baz']),
+ NS(foodle=None, foonly=None, fo=None, foonew='baz'))
+ self.assertEqual(parser.parse_args(['bar', '--foon', 'baz']),
+ NS(foodle=None, foonly=None, fo=None, foonew='baz'))
+ self.assertArgumentParserError(parser.parse_args, ['bar', '--food', 'baz'])
+
  def test_parse_known_args_with_single_dash_option(self):
  parser = ErrorRaisingArgumentParser()
  parser.add_argument('-k', '--known', action='count', default=0)

Misc/NEWS.d/next/Library/2024-09-26-22-14-12.gh-issue-58573.hozbm9.rst

@@ -0,0 +1,2 @@
+Fix conflicts between abbreviated long options in the parent parser and
+subparsers in :mod:`argparse`.