fix corner case in loops & unused (#4083)

fixes #4082
2020-08-28 19:42:17 +01:00
parent b1cc15e85b
commit f886b3fb2b
2 changed files with 25 additions and 1 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -4800,7 +4800,7 @@ merge(Compressor.prototype, {
                return true;
            }
            if (node instanceof AST_ForIn) {
-                if (!compressor.option("loops")) return;
+                if (!drop_vars || !compressor.option("loops")) return;
                if (!is_empty(node.body)) return;
                if (node.init.has_side_effects(compressor)) return;
                node.object.walk(tw);