fix corner case in `loops` & `unused` (#4241)

fixes #4240

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/compress.js b/lib/compress.js
index c6e27e06..216ca92a 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -5182,7 +5182,7 @@ merge(Compressor.prototype, {
                 var def = sym.definition();
                 if (!def) return;
                 if (def.id in in_use_ids) return;
-                if (def.scope !== self && member(def, self.enclosed)) return;
+                if (def.scope !== self && self.find_variable(sym) === def) return;
                 log(sym, "Dropping unused loop variable {name}");
                 if (for_ins[def.id] === node) delete for_ins[def.id];
                 var body = [];