1 files changed, 32 insertions, 6 deletions

diff --git a/lib/compress.js b/lib/compress.js
index c8b15ffc..6062be54 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -3553,7 +3553,9 @@ merge(Compressor.prototype, {
                 return make_node(AST_Infinity, self).optimize(compressor);
             }
         }
-        if (compressor.option("evaluate") && compressor.option("reduce_vars")) {
+        if (compressor.option("evaluate")
+            && compressor.option("reduce_vars")
+            && is_lhs(self, compressor.parent()) !== self) {
             var d = self.definition();
             var fixed = self.fixed_value();
             if (fixed) {
@@ -3561,21 +3563,45 @@ merge(Compressor.prototype, {
                     var init = fixed.evaluate(compressor);
                     if (init !== fixed) {
                         init = make_node_from_constant(init, fixed);
-                        var value = best_of_expression(init.optimize(compressor), fixed).print_to_string().length;
+                        var value = init.optimize(compressor).print_to_string().length;
+                        var fn;
+                        if (has_symbol_ref(fixed)) {
+                            fn = function() {
+                                var result = init.optimize(compressor);
+                                return result === init ? result.clone(true) : result;
+                            };
+                        } else {
+                            value = Math.min(value, fixed.print_to_string().length);
+                            fn = function() {
+                                var result = best_of_expression(init.optimize(compressor), fixed);
+                                return result === init || result === fixed ? result.clone(true) : result;
+                            };
+                        }
                         var name = d.name.length;
-                        var freq = d.references.length;
-                        var overhead = d.global || !freq ? 0 : (name + 2 + value) / freq;
-                        d.should_replace = value <= name + overhead ? init : false;
+                        var overhead = 0;
+                        if (compressor.option("unused") && (!d.global || compressor.option("toplevel"))) {
+                            overhead = (name + 2 + value) / d.references.length;
+                        }
+                        d.should_replace = value <= name + overhead ? fn : false;
                     } else {
                         d.should_replace = false;
                     }
                 }
                 if (d.should_replace) {
-                    return best_of_expression(d.should_replace.optimize(compressor), fixed).clone(true);
+                    return d.should_replace();
                 }
             }
         }
         return self;
+
+        function has_symbol_ref(value) {
+            var found;
+            value.walk(new TreeWalker(function(node) {
+                if (node instanceof AST_SymbolRef) found = true;
+                if (found) return true;
+            }));
+            return found;
+        }
     });
 
     function is_atomic(lhs, self) {