-/* Report an error for an out-of-range integer argument.
- EXIT_CODE is the exit code (0 for a non-fatal error).
- OPTION is the option that takes the argument
- (usually starting with one or two minus signs).
- ARG is the option's argument.
- ERR is the error code returned by one of the xstrto* functions. */
-void
-xstrtol_error (int exit_code, char const *option, char const *arg,
- strtol_error err)
+/* Report an error for an invalid integer in an option argument.
+
+ ERR is the error code returned by one of the xstrto* functions.
+
+ Use OPT_IDX to decide whether to print the short option string "C"
+ or "-C" or a long option string derived from LONG_OPTION. OPT_IDX
+ is -2 if the short option "C" was used, without any leading "-"; it
+ is -1 if the short option "-C" was used; otherwise it is an index
+ into LONG_OPTIONS, which should have a name preceded by two '-'
+ characters.
+
+ ARG is the option-argument containing the integer.
+
+ After reporting an error, exit with status EXIT_STATUS if it is
+ nonzero. */
+
+static void
+xstrtol_error (enum strtol_error err,
+ int opt_idx, char c, struct option const *long_options,
+ char const *arg,
+ int exit_status)