fix corner case in evaluate (#3888)

fixes #3887
2020-05-12 10:58:37 +01:00
parent ee7647dc67
commit eb7fa25270
2 changed files with 24 additions and 1 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -3368,7 +3368,7 @@ merge(Compressor.prototype, {
        });
        def(AST_UnaryPostfix, function(compressor, ignore_side_effects, cached, depth) {
            var e = this.expression;
-            if (!(e instanceof AST_SymbolRef)) return this;
+            if (!e.fixed) return this;
            var refs = e.definition().references;
            if (!ignore_side_effects && refs[refs.length - 1] !== e) return this;
            var v = e._eval(compressor, ignore_side_effects, cached, depth + 1);