fix corner case with parentheses (#4409)

fixes #4408
2020-12-18 17:01:49 +00:00
parent 44e494f16f
commit 7d9dad0289
2 changed files with 79 additions and 5 deletions
--- a/lib/output.js
+++ b/lib/output.js
@@ -1198,11 +1198,9 @@ function OutputStream(options) {
        // need to take some precautions here:
        //    https://github.com/mishoo/UglifyJS/issues/60
        if (noin) node.walk(new TreeWalker(function(node) {
-            if (parens || node instanceof AST_Scope) return true;
-            if (node instanceof AST_Binary && node.operator == "in") {
-                parens = true;
-                return true;
-            }
+            if (parens) return true;
+            if (node instanceof AST_Binary && node.operator == "in") return parens = true;
+            if (node instanceof AST_Scope && !(node instanceof AST_Arrow && node.value)) return true;
        }));
        node.print(output, parens);
    }