commit 15fec5627ac343afd0bfa1e847746071982d5172
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Fri Jun 05 17:13:14 2020 -0700
committer GitHub <noreply@github.com> Fri Jun 05 17:13:14 2020 -0700
tree 4da7778e569651b14f0986d867348d77590b427b
parent 79e6c15aed9b4b50efd39ddaf1dc40c374b51213

bpo-40880: Fix invalid read in newline_in_string in pegen.c (GH-20666)


* bpo-40880: Fix invalid read in newline_in_string in pegen.c

* Update Parser/pegen/pegen.c

Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>

* Add NEWS entry

Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
(cherry picked from commit 2e6593db0086004a1ca7f7049218ff9573d473c2)

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>

Parser/pegen/pegen.c

diff --git a/Parser/pegen/pegen.c b/Parser/pegen/pegen.c
index 6608fd8..76442de 100644
--- a/Parser/pegen/pegen.c
+++ b/Parser/pegen/pegen.c
@@ -936,8 +936,8 @@
 static int // bool
 newline_in_string(Parser *p, const char *cur)
 {
-    for (char c = *cur; cur >= p->tok->buf; c = *--cur) {
-        if (c == '\'' || c == '"') {
+    for (const char *c = cur; c >= p->tok->buf; c--) {
+        if (*c == '\'' || *c == '"') {
             return 1;
         }
     }