From 8ed90d3af2537628c8c716e0a9cda3d47f0f9c3f Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Thu, 7 May 2015 01:58:54 +0100
Subject: [PATCH] ignore parameter bindings in minification.deadCodeElimination
 transformer - fixes #1464

---
 .../transformers/minification/dead-code-elimination.js           | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/babel/transformation/transformers/minification/dead-code-elimination.js b/src/babel/transformation/transformers/minification/dead-code-elimination.js
index d5c975f6ac..2d840f991e 100644
--- a/src/babel/transformation/transformers/minification/dead-code-elimination.js
+++ b/src/babel/transformation/transformers/minification/dead-code-elimination.js
@@ -26,6 +26,7 @@ export function Identifier(node, parent, scope) {
 
   var binding = scope.getBinding(node.name);
   if (!binding || binding.references > 1 || !binding.constant) return;
+  if (binding.kind === "param") return;
 
   var replacement = binding.path.node;
   if (t.isVariableDeclarator(replacement)) {