fix corner case in collapse_vars (#3627)

fixes #3626
2019-12-05 00:59:57 +08:00
parent d68ddc31f9
commit bf7e4ca1a3
2 changed files with 42 additions and 3 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1578,9 +1578,11 @@ merge(Compressor.prototype, {
                }
                if (parent instanceof AST_Binary) {
                    if (lazy_op[parent.operator] && parent.left !== node) {
-                        var grandparent = scanner.parent(level + 1);
-                        if (!(grandparent instanceof AST_Binary)) return node;
-                        if (grandparent.operator != parent.operator) return node;
+                        do {
+                            node = parent;
+                            parent = scanner.parent(++level);
+                        } while (parent instanceof AST_Binary && parent.operator == node.operator);
+                        return node;
                    }
                    return find_stop_value(parent, level + 1);
                }