[Bug c/81859] New: valgrind error from warn_about_normalization

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81859

            Bug ID: 81859
           Summary: valgrind error from warn_about_normalization
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

For the C testsuite file c-c++-common/cpp/normalize-3.c,
a valgrind build of trunk gcc revision 251105 does this:

c-c++-common/cpp/normalize-3.c:5:1: error: unknown type name ‘ª’
 \u00AA
 ^~~~~~
==24049== Conditional jump or move depends on uninitialised value(s)
==24049==    at 0x4C31B98: strlen (vg_replace_strmem.c:458)
==24049==    by 0x112A520: pp_format(pretty_printer*, text_info*)
(pretty-print.
c:676)
==24049==    by 0x112322E: diagnostic_report_diagnostic(diagnostic_context*,
dia
gnostic_info*) (diagnostic.c:974)
==24049==    by 0x61977A: c_cpp_error(cpp_reader*, int, int, rich_location*,
cha
r const*, __va_list_tag (*) [1]) (c-common.c:6128)
==24049==    by 0x1139A20: cpp_diagnostic_with_line(cpp_reader*, int, int,
unsig
ned int, unsigned int, char const*, __va_list_tag (*) [1]) (errors.c:174)
==24049==    by 0x1139DE8: cpp_warning_with_line(cpp_reader*, int, unsigned
int,
 unsigned int, char const*, ...) (errors.c:210)
==24049==    by 0x1142B97: warn_about_normalization(cpp_reader*, cpp_token
const
*, normalize_state const*) [clone .isra.11] [clone .part.12] (lex.c:1310)
==24049==    by 0x114521C: warn_about_normalization (lex.c:2916)

Revision 250947 doesn't have this problem, so it looks new to me.