File perl-regcomp-N-parse.diff of Package perl.6851

--- ./regcomp.c.orig	2017-10-25 14:03:20.964427277 +0000
+++ ./regcomp.c	2017-10-25 14:05:03.214156095 +0000
@@ -10032,12 +10032,15 @@ S_grok_bslash_N(pTHX_ RExC_state_t *pREx
 	}
 	sv_catpv(substitute_parse, ")");
 
-	RExC_parse = SvPV(substitute_parse, len);
+	len = SvCUR(substitute_parse);
 
 	/* Don't allow empty number */
 	if (len < 8) {
 	    vFAIL("Invalid hexadecimal number in \\N{U+...}");
 	}
+
+	RExC_parse = SvPV(substitute_parse, len);
+
 	RExC_end = RExC_parse + len;
 
 	/* The values are Unicode, and therefore not subject to recoding */