Fix bug #17776 : memory corruption in qr/##/x

p4raw-id: //depot/perl@17994

diff --git a/sv.c b/sv.c
index 2017045..f5b9849 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -3006,6 +3006,7 @@ Perl_sv_2pv_flags(pTHX_ register SV *sv, STRLEN *lp, I32 flags)
                                            need a newline */
                                         mg->mg_len++; /* save space for it */
                                         need_newline = 1; /* note to add it */
+                                       break;
                                     }
                                 }
                             }

diff --git a/t/op/pat.t b/t/op/pat.t
index 4ef860c..6a1d602 100755 (executable)
--- a/t/op/pat.t
+++ b/t/op/pat.t
@@ -6,7 +6,7 @@
 
 $| = 1;
 
-print "1..940\n";
+print "1..941\n";
 
 BEGIN {
     chdir 't' if -d 't';
@@ -2931,6 +2931,10 @@ print(("a$x" =~ /^a(??{$a})\z/ ? '' : 'not '),
       "ok $test - postponed interpolation of qr// preserves utf8\n");
 ++$test;
 
+print((length(qr/##/x) == 12 ? '' : 'not '),
+      "ok $test - ## in qr// doesn't corrupt memory [perl #17776]\n");
+++$test;
+
 { use re 'eval';
 
 print(("$x$x" =~ /^$x(??{$x})\z/ ? '' : 'not '),