In the code I've just uploaded, line 14 and 15 whenever I remove the surrounding bracket in if condition, xdebug is jumps out over the line. Even if you add a break-point in the function itself, its not able to break there too.

Problem will gone whenver you add the surronding brackets.

It won't break on foo_bar:

if ($x == 1)
$y->foo_bar(10);

It breaks on foo_bar:

if ($x == 1) {
$y->foo_bar(10);
}