PHP: Inconsistent try...finally blocks are expected to return the same value, but don't.

inconsistent_try_finally.php

<?php
function fubar1($foo = 1){
    _($foo, 1);
    try{
    	$foo++; // even works when $foo modified in this block
        _($foo);
        return $foo; // only works when bare $foo returned
    } finally {
        _($foo);
        $foo++;
        _($foo);
    }
}

function fubar2($foo = 1){
    _($foo, 1);
    try{
    	$foo++;
        _($foo);
        return $foo + 0;
	// it also happens when returning...
	// intval($foo), strval($foo), -(-$foo), +$foo
    } finally {
        _($foo);
        $foo++; // this is ignored
        _($foo);
    }
}

function _($x, $n = null) {
    global $m;
    $m = is_null($n) ? ++$m : $n;
    print "    Step ${m}: $x" . PHP_EOL;
}

print 'Result 1: ' . fubar1() . PHP_EOL; // returns 3, correct
print 'Result 2: ' . fubar2() . PHP_EOL; // returns 2, wrong and inconsistent with fubar1()

// Results
/*
    Step 1: 1
    Step 2: 2
    Step 3: 2
    Step 4: 3
Result 1: 3
    Step 1: 1
    Step 2: 2
    Step 3: 2
    Step 4: 3
Result 2: 2
 */