workaround v8 bug with labels (#4467)

closes #4466

1 files changed, 10 insertions, 1 deletions

diff --git a/lib/scope.js b/lib/scope.js
index c59dc0a7..0c35b0dd 100644
--- a/lib/scope.js
+++ b/lib/scope.js
@@ -512,6 +512,7 @@ function _default_mangler_options(options) {
         keep_fnames : false,
         reserved    : [],
         toplevel    : false,
+        v8          : false,
         webkit      : false,
     });
     if (!Array.isArray(options.reserved)) options.reserved = [];
@@ -543,7 +544,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             // lname is incremented when we get to the AST_Label
             var save_nesting = lname;
             descend();
-            lname = save_nesting;
+            if (!options.v8 || !in_label(tw)) lname = save_nesting;
             return true;
         }
         if (node instanceof AST_BlockScope) {
@@ -616,6 +617,14 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             sym.thedef = def;
         }
     }
+
+    function in_label(tw) {
+        var level = 0, parent;
+        while (parent = tw.parent(level++)) {
+            if (parent instanceof AST_Block) return parent instanceof AST_Toplevel && !options.toplevel;
+            if (parent instanceof AST_LabeledStatement) return true;
+        }
+    }
 });
 
 AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {