fix corner case in assignments (#3430)

fixes #3429
2019-05-30 05:01:53 +08:00
parent 482e1baea3
commit 9d3b1efd86
2 changed files with 47 additions and 1 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -3856,7 +3856,7 @@ merge(Compressor.prototype, {
            if (!(rhs instanceof AST_Binary && lazy_op[rhs.operator])) return rhs;
            var sym = assign.left;
            if (!(sym instanceof AST_SymbolRef) || sym.name != rhs.left.name) return rhs;
-            return rhs.right;
+            return rhs.right.has_side_effects(compressor) ? rhs : rhs.right;
        }

        function scan_ref_scoped(node, descend) {