+PERL_STATIC_INLINE UV
+Perl_utf8_to_uvchr_buf_helper(pTHX_ const U8 *s, const U8 *send, STRLEN *retlen)
+{
+ PERL_ARGS_ASSERT_UTF8_TO_UVCHR_BUF_HELPER;
+
+ assert(s < send);
+
+ if (! ckWARN_d(WARN_UTF8)) {
+
+ /* EMPTY is not really allowed, and asserts on debugging builds. But
+ * on non-debugging we have to deal with it, and this causes it to
+ * return the REPLACEMENT CHARACTER, as the documentation indicates */
+ return utf8n_to_uvchr(s, send - s, retlen,
+ (UTF8_ALLOW_ANY | UTF8_ALLOW_EMPTY));
+ }
+ else {
+ UV ret = utf8n_to_uvchr(s, send - s, retlen, 0);
+ if (retlen && ret == 0 && *s != '\0') {
+ *retlen = (STRLEN) -1;
+ }
+
+ return ret;
+ }
+}
+