fix corner case in collapse_vars (#3972)

fixes #3971
2020-06-08 17:09:21 +01:00
parent 491d6ce1d5
commit 5561d3e7f3
2 changed files with 52 additions and 5 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1258,7 +1258,7 @@ merge(Compressor.prototype, {
                        col: node.start.col
                    });
                    if (candidate instanceof AST_UnaryPostfix) {
-                        delete candidate.expression.fixed;
+                        lhs.definition().fixed = false;
                        return make_node(AST_UnaryPrefix, candidate, candidate);
                    }
                    if (candidate instanceof AST_VarDef) {