fix corner case in merge_vars (#4629)

fixes #4628
2021-02-09 04:36:12 +00:00
parent e13d1e9969
commit fcee32527b
2 changed files with 36 additions and 2 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -5276,8 +5276,13 @@ merge(Compressor.prototype, {
                return true;
            }
            if (node instanceof AST_VarDef) {
-                if (node.value) node.value.walk(tw);
-                node.name.mark_symbol(node.value ? function(node) {
+                var assigned = node.value;
+                if (assigned) {
+                    assigned.walk(tw);
+                } else {
+                    assigned = segment.block instanceof AST_ForEnumeration && segment.block.init === tw.parent();
+                }
+                node.name.mark_symbol(assigned ? function(node) {
                    if (!(node instanceof AST_SymbolDeclaration)) return;
                    if (node instanceof AST_SymbolVar) {
                        mark(node);