HowTo

To run the test-case:

git clone https://github.com/tex0l/bug-report-babel.git
npm install
npm start
cat build/dest.js

TLDR

Input:

function test () {
  if (true) return
  var i
  for (var l=1; i < l; i++) {}
}

Actual output:

function test(){if(false)for(var i,l=1;i<undefined;i++);}

Expected output:

function test(){if(false)for(var i,l=1;i<l;i++);}