Make _charnames comparison null-safe

This comparison in toke.c checks whether the charnames translators is
the core’s own and, if so, skips certain validation checks.

Charnames translators coming from any package beginning with
"_charnames\0" would also be exempt from the checks, because the name
comparison stopped at the first null.

1 files changed, 2 insertions, 1 deletions

diff --git a/toke.c b/toke.c
index d7de0dbfdf..d871fc46e7 100644
--- a/toke.c
+++ b/toke.c
@@ -2859,7 +2859,8 @@ S_get_and_check_backslash_N_name(pTHX_ const char* s, const char* const e)
         SvTYPE(rv) == SVt_PVCV) && ((stash = CvSTASH(rv)) != NULL))
     {
         const char * const name = HvNAME(stash);
-        if strEQ(name, "_charnames") {
+        if (HvNAMELEN(stash) == sizeof("_charnames")-1
+         && strEQ(name, "_charnames")) {
            return res;
        }
     }