fix corner case in `reduce_vars` (#3141)

fixes #3140

1 files changed, 12 insertions, 1 deletions

diff --git a/lib/compress.js b/lib/compress.js
index efc7c47f..498729d0 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -380,6 +380,16 @@ merge(Compressor.prototype, {
                     mark(tw, def, true);
                 }
             });
+            scope.may_call_this = function() {
+                scope.may_call_this = noop;
+                if (!scope.contains_this()) return;
+                scope.functions.each(function(def) {
+                    if (def.init instanceof AST_Defun && !(def.id in tw.defun_ids)) {
+                        tw.defun_ids[def.id] = false;
+                    }
+                });
+                return true;
+            };
         }
 
         function mark_defun(tw, def) {
@@ -556,6 +566,7 @@ merge(Compressor.prototype, {
             return true;
         });
         def(AST_Call, function(tw, descend) {
+            if (tw.find_parent(AST_Scope).may_call_this()) return;
             var exp = this.expression;
             if (!(exp instanceof AST_SymbolRef)) return;
             var def = exp.definition();
@@ -6278,7 +6289,7 @@ merge(Compressor.prototype, {
         return self;
     });
 
-    AST_Lambda.DEFMETHOD("contains_this", function() {
+    AST_Scope.DEFMETHOD("contains_this", function() {
         var result;
         var self = this;
         self.walk(new TreeWalker(function(node) {