[njs] Parser: fixed heap-use-after-free in optional chain.

[Alexander Borisov]

details:   https://hg.nginx.org/njs/rev/341cd52d4348
branches:  
changeset: 1437:341cd52d4348
user:      Alexander Borisov <alexander.borisov at nginx.com>
date:      Fri Jun 19 19:48:12 2020 +0300
description:
Parser: fixed heap-use-after-free in optional chain.

diffstat:

 src/njs_parser.c         |  4 ----
 src/test/njs_unit_test.c |  3 +++
 2 files changed, 3 insertions(+), 4 deletions(-)

diffs (27 lines):

diff -r a712d6442c0a -r 341cd52d4348 src/njs_parser.c
--- a/src/njs_parser.c	Thu Jun 18 18:56:24 2020 +0000
+++ b/src/njs_parser.c	Fri Jun 19 19:48:12 2020 +0300
@@ -2881,10 +2881,6 @@ njs_parser_optional_chain(njs_parser_t *
         break;
 
     default:
-        if (!njs_lexer_token_is_identifier_name(token)) {
-            njs_lexer_consume_token(parser->lexer, 1);
-        }
-
         ret = njs_parser_property(parser, token, current);
 
         switch (ret) {
diff -r a712d6442c0a -r 341cd52d4348 src/test/njs_unit_test.c
--- a/src/test/njs_unit_test.c	Thu Jun 18 18:56:24 2020 +0000
+++ b/src/test/njs_unit_test.c	Fri Jun 19 19:48:12 2020 +0300
@@ -17016,6 +17016,9 @@ static njs_unit_test_t  njs_test[] =
 
     { njs_str("{{} ({a: 1, b: {}\n}\n})\n}"),
       njs_str("SyntaxError: Unexpected token \"}\" in 3") },
+
+    { njs_str("object?."),
+      njs_str("SyntaxError: Unexpected end of input in 1") },
 };