[issue14364] Argparse incorrectly handles '--' as argument to option

[hai shi]

hai shi <shihai1991 at 126.com> added the comment:

some test cases which paul provided looks doesn't keep compatible.

In TestDoubleDashRemoval:
# output in my env is Namespace(cmd='cmd', foo=None, rest=['--', '--foo'])
('-- cmd -- -- --foo', NS(cmd='cmd', foo=None, rest=['--', '--', '--foo']))

# output in my env is Namespace(cmd='--', foo='1', rest=['1', '2'])
('-f1 -- -- 1 -- 2', NS(cmd='--', foo='1', rest=['1', '--', '2']))

# output in my env is Namespace(cmd='--foo', foo=None, rest=['--bar', '2'])
('-- --foo -- --bar 2', NS(cmd='--foo', foo=None, rest=['--', '--bar', '2']))

# output in my env is Namespace(cmd='cmd', foo=None, rest=['--foo', '-f2'])
('cmd -- --foo -- -f2', NS(cmd='cmd', foo=None, rest=['--foo', '--', '-f2']))


In TestDoubleDashRemoval1:
# output in my env is Namespace(cmd='cmd', foo='1', rest=['-f2', '3'])
('-f1 -- cmd -- -f2 3', NS(cmd='cmd', foo='1', rest=['--', '-f2', '3']))

my python's version is: 2.7.5, 3.6.8

----------
nosy: +shihai1991

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue14364>
_______________________________________