When stepping trough this kind of code using step over:

if ($var){
$test = "azerty";
}

Xdebug stops at the "if", then the test line: this is ok. However with this code:

if ($var)
{
$test = "azerty";
}

Xdebugs skips the "if" but steps on the opening curly brace, then steps on the test line. And finally with this:

if ($var)
$test = "azerty";

the "if" line is skipped and Xdebug step directly to the test line.