From 1770ccaecd7419bf6ba353c35b0004d91ce06c3c Mon Sep 17 00:00:00 2001
From: Robert Fancsik <frobert@inf.u-szeged.hu>
Date: Fri, 5 Jun 2020 13:25:05 +0200
Subject: [PATCH] Object/Array initializers should be parsed as
 AssignmentExpression (#3851)

This patch fixes #3849.

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu
---
 jerry-core/parser/js/js-parser-expr.c         | 14 ++++++-------
 .../es2015/regression-test-issue-3849.js      | 21 +++++++++++++++++++
 2 files changed, 28 insertions(+), 7 deletions(-)
 create mode 100644 tests/jerry/es2015/regression-test-issue-3849.js

diff --git a/jerry-core/parser/js/js-parser-expr.c b/jerry-core/parser/js/js-parser-expr.c
index 565de930a..69e42338e 100644
--- a/jerry-core/parser/js/js-parser-expr.c
+++ b/jerry-core/parser/js/js-parser-expr.c
@@ -1581,14 +1581,14 @@ parser_check_assignment_expr (parser_context_t *context_p)
 } /* parser_check_assignment_expr */
 
 /**
- * Checks whether the next token is a valid continuation token after an arrow function.
+ * Checks whether the next token is a valid continuation token after an AssignmentExpression.
  */
 static inline bool JERRY_ATTR_ALWAYS_INLINE
-parser_abort_parsing_after_arrow (parser_context_t *context_p)
+parser_abort_parsing_after_assignment_expression (parser_context_t *context_p)
 {
   return (context_p->token.type != LEXER_RIGHT_PAREN
           && context_p->token.type != LEXER_COMMA);
-} /* parser_abort_parsing_after_arrow */
+} /* parser_abort_parsing_after_assignment_expression */
 
 #endif /* ENABLED (JERRY_ES2015) */
 
@@ -1732,7 +1732,7 @@ parser_parse_unary_expression (parser_context_t *context_p, /**< context */
 
         parser_check_assignment_expr (context_p);
         parser_parse_function_expression (context_p, arrow_status_flags);
-        return parser_abort_parsing_after_arrow (context_p);
+        return parser_abort_parsing_after_assignment_expression (context_p);
       }
 #endif /* ENABLED (JERRY_ES2015) */
 
@@ -1828,7 +1828,7 @@ parser_parse_unary_expression (parser_context_t *context_p, /**< context */
         if (parser_is_assignment_expr (context_p))
         {
           parser_parse_object_initializer (context_p, PARSER_PATTERN_NO_OPTS);
-          return false;
+          return parser_abort_parsing_after_assignment_expression (context_p);
         }
 
         scanner_release_next (context_p, sizeof (scanner_location_info_t));
@@ -1848,7 +1848,7 @@ parser_parse_unary_expression (parser_context_t *context_p, /**< context */
         if (parser_is_assignment_expr (context_p))
         {
           parser_parse_array_initializer (context_p, PARSER_PATTERN_NO_OPTS);
-          return false;
+          return parser_abort_parsing_after_assignment_expression (context_p);
         }
 
         scanner_release_next (context_p, sizeof (scanner_location_info_t));
@@ -1949,7 +1949,7 @@ parser_parse_unary_expression (parser_context_t *context_p, /**< context */
       parser_check_assignment_expr (context_p);
 
       parser_parse_function_expression (context_p, PARSER_IS_FUNCTION | PARSER_IS_ARROW_FUNCTION);
-      return parser_abort_parsing_after_arrow (context_p);
+      return parser_abort_parsing_after_assignment_expression (context_p);
     }
     case LEXER_KEYW_YIELD:
     {
diff --git a/tests/jerry/es2015/regression-test-issue-3849.js b/tests/jerry/es2015/regression-test-issue-3849.js
new file mode 100644
index 000000000..cfcdb7941
--- /dev/null
+++ b/tests/jerry/es2015/regression-test-issue-3849.js
@@ -0,0 +1,21 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+try {
+  eval(`[]=$--['']`);
+  assert(false);
+} catch (e) {
+  assert(e instanceof SyntaxError);
+}
+