X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=regcomp.c;h=7c8c3911db8c9da4638f673636089547a401d694;hb=37be2b3976e33708042402101fbafebc36dcb7a3;hp=99cb4645e9962595eedab7061956cf6f711bc957;hpb=6bdeddd23b939aa3cc0ba14b253df11198918e70;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/regcomp.c b/regcomp.c
index 99cb464..7c8c391 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -4944,9 +4944,13 @@ Perl_reg_named_buff_exists(pTHX_ REGEXP * const rx, SV * const key,
 SV*
 Perl_reg_named_buff_firstkey(pTHX_ REGEXP * const rx, const U32 flags)
 {
-    (void)hv_iterinit(rx->paren_names);
+    if ( rx && rx->paren_names ) {
+	(void)hv_iterinit(rx->paren_names);
 
-    return CALLREG_NAMED_BUFF_NEXTKEY(rx, NULL, flags & ~RXapif_FIRSTKEY);
+	return CALLREG_NAMED_BUFF_NEXTKEY(rx, NULL, flags & ~RXapif_FIRSTKEY);
+    } else {
+	return FALSE;
+    }
 }
 
 SV*
@@ -6894,6 +6898,11 @@ tryagain:
 	    RExC_seen_zerolen++;
 	    ret = reg_node(pRExC_state, KEEPS);
 	    *flagp |= SIMPLE;
+	    /* XXX:dmq : disabling in-place substitution seems to
+	     * be necessary here to avoid cases of memory corruption, as
+	     * with: C<$_="x" x 80; s/x\K/y/> -- rgs
+	     */
+	    RExC_seen |= REG_SEEN_LOOKBEHIND;
 	    goto finish_meta_pat;
 	case 'Z':
 	    ret = reg_node(pRExC_state, SEOL);