enhance reduce_vars & varify (#4714)

2021-03-02 07:27:55 +00:00
parent ee27d87a08
commit 74dee5c445
3 changed files with 56 additions and 3 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1259,10 +1259,13 @@ merge(Compressor.prototype, {
        });
        def(AST_VarDef, function(tw, descend, compressor) {
            var node = this;
-            if (!node.value) return;
-            node.value.walk(tw);
+            if (node.value) {
+                node.value.walk(tw);
+            } else if (!(tw.parent() instanceof AST_Let)) {
+                return;
+            }
            scan_declaration(tw, compressor, node.name, function() {
-                return node.value;
+                return node.value || make_node(AST_Undefined, node);
            }, function(name, fixed) {
                var d = name.definition();
                if (fixed && safe_to_assign(tw, d, true)) {