fix corner case in merge_vars (#4104)

fixes #4103
2020-09-15 12:47:12 +01:00
parent d64d0b0bec
commit 335456cf77
2 changed files with 29 additions and 1 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -4315,10 +4315,11 @@ merge(Compressor.prototype, {
        var prev = Object.create(null);
        var tw = new TreeWalker(function(node, descend) {
            if (node instanceof AST_Assign) {
+                if (node.operator != "=") return;
                var sym = node.left;
                if (!(sym instanceof AST_SymbolRef)) return;
                node.right.walk(tw);
-                mark(sym, node.operator == "=");
+                mark(sym, true);
                return true;
            }
            if (node instanceof AST_Binary) {