There were two copies of the bulk of the code to handle long options.
Now there is only one. (Yes, this is in aid of merging from gnulib.)
The change to bug-getopt4.c clarifies the error messages when the test
fails.
* posix/getopt.c (process_long_option): New function split out
from _getopt_internal_r.
(_getopt_internal_r): Replace both copies of the long-option
processing code with calls to process_long_option.
* posix/bug-getopt4.c (one_test): Print argv[0] in error messages.
(do_test): Differentiate argv[0] in the two subtests.
