argp: fix handling of very long options in --help

* lib/argp-help.c (hol_entry_help): Handle cases with option
description is larger than RMARGIN.

lib/argp-help.c

@@ -1186,7 +1186,11 @@ hol_entry_help (struct hol_entry *entry, const struct argp_state *state,
           __argp_fmtstream_set_lmargin (stream, uparams.opt_doc_col);
           __argp_fmtstream_set_wmargin (stream, uparams.opt_doc_col);
 
-          if (col > (unsigned int) (uparams.opt_doc_col + 3))
+          /* Put the description on a new line if it cannot start
+             within 3 columns of OPT_DOC_COL.  Note that if the option
+             specification went past RMARGIN, then COL has been reset
+             to 0. */
+          if (col > (unsigned int) (uparams.opt_doc_col + 3) || col == 0)
             __argp_fmtstream_putc (stream, '\n');
           else if (col >= (unsigned int) uparams.opt_doc_col)
             __argp_fmtstream_puts (stream, "   ");