https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101399
--- Comment #6 from Steve Kargl <kargl at gcc dot gnu.org> ---
(In reply to Steve Kargl from comment #3)
> diff --git a/gcc/fortran/io.c b/gcc/fortran/io.c
> index 40cd76eb585..8c3f841098f 100644
> --- a/gcc/fortran/io.c
> +++ b/gcc/fortran/io.c
> @@ -4226,7 +4226,10 @@ match_io (io_kind k)
>
> if (gfc_current_form == FORM_FREE)
> {
> - char c = gfc_peek_ascii_char ();
> + char c;
> +
> + gfc_gobble_whitespace ();
> + c = gfc_peek_ascii_char ();
> if (c != ' ' && c != '*' && c != '\'' && c != '"')
> {
> m = MATCH_NO;
>
This simple patch does not regression test cleanly.
Many of the failures are due to other work-a-rounds
for accepting invalid uses of a tab.
