fix `hoist_vars` on `reduce_vars` (#1607)

`hoist_vars` converts variable declarations into plain assignments, which then confuses `reduce_vars`

fixes #1606

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/compress.js b/lib/compress.js
index b3004fb5..49b618e7 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1986,7 +1986,7 @@ merge(Compressor.prototype, {
                                 vars.set(def.name.name, def);
                                 ++vars_found;
                             });
-                            var seq = node.to_assignments();
+                            var seq = node.to_assignments(compressor);
                             var p = tt.parent();
                             if (p instanceof AST_ForIn && p.init === node) {
                                 if (seq == null) {
@@ -2579,7 +2579,8 @@ merge(Compressor.prototype, {
         this.definitions.forEach(function(def){ def.value = null });
     });
 
-    AST_Definitions.DEFMETHOD("to_assignments", function(){
+    AST_Definitions.DEFMETHOD("to_assignments", function(compressor){
+        var reduce_vars = compressor.option("reduce_vars");
         var assignments = this.definitions.reduce(function(a, def){
             if (def.value) {
                 var name = make_node(AST_SymbolRef, def.name, def.name);
@@ -2588,6 +2589,7 @@ merge(Compressor.prototype, {
                     left     : name,
                     right    : def.value
                 }));
+                if (reduce_vars) name.definition().fixed = false;
             }
             return a;
         }, []);