regcomp.c: Don't read past string-end

In doing an audit of regcomp.c, and experimenting using
Encode::_utf8_on(), I found this one instance of a regen/regcharclass.pl
macro that could read beyond the end of the string if given malformed
UTF-8.  Hence we convert to use the 'safe' form.  There are no other
uses of the non-safe version, so don't need to generate them.

1 files changed, 1 insertions, 1 deletions

diff --git a/regcomp.c b/regcomp.c
index d72d3441bf..ca2ffb8d48 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -11920,7 +11920,7 @@ tryagain:
                     if (! SIZE_ONLY
                         && RExC_flags & RXf_PMf_EXTENDED
                         && ckWARN_d(WARN_DEPRECATED)
-                        && is_PATWS_non_low(p, UTF))
+                        && is_PATWS_non_low_safe(p, RExC_end, UTF))
                     {
                         vWARN_dep(p + ((UTF) ? UTF8SKIP(p) : 1),
                                 "Escape literal pattern white space under /x");