Description:
------------
$this is assigned incorrectly. See the sample code below.

Reproduce code:
---------------
<?

class abc {
 function a() { echo "abc::a\n"; $this->b(); }
 function b() { echo "abc::b\n"; }
}

class def {
 function c() { echo "def::c\n"; abc::a(); }
}

$test = new def();
$test->c();


Expected result:
----------------
def::c abc::a
some error message

Actual result:
--------------
def::c abc::a
Fatal error: Call to undefined method def::b() in ...php on line 4