"if" condition is incorrectly omitted after minify

[runtarm]

Input Code

if (false) {
  var bar = true;
}
if (bar) {
  alert('bug!');
}

Actual Output

var bar;alert('bug!');

Expected Output

var bar;bar&&alert('bug!');

Details

The if condition is incorrectly removed. The logic is changed.

I know that putting var inside a block scope is definitely a bad practice. I've just tried to minify some legacy codes and encountered this critical issue.

Example: See it here in repl