fix corner case in merge_vars (#4957)

fixes #4956
2021-05-24 02:56:02 +01:00
parent 8b0c836515
commit eb08fed120
3 changed files with 79 additions and 2 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -5789,7 +5789,7 @@ merge(Compressor.prototype, {
                if (!tail_refs) continue;
                if (head_refs.start.block !== tail_refs.start.block
                    || !mergeable(head_refs, tail_refs)
-                    || head_refs.start.loop && !mergeable(tail_refs, head_refs)
+                    || (head_refs.start.loop || !same_scope(def)) && !mergeable(tail_refs, head_refs)
                    || !all(tail_refs, function(sym) {
                        return sym.scope.find_variable(def.name) === def;
                    })) {