Description:
------------
When running with APC 3.1.9, this code produces an error. Without APC it runs as expected.  Works as expected with APC 3.1.9 on PHP 5.3.9.

APC settings:

extension = apc.so
apc.enabled=1



Test script:
---------------
abstract class Dog {
    public abstract function bark();
}
abstract class SmallDog extends Dog {
}
class Charlie extends SmallDog {
    function bark() {
        echo "woof!";
    }
}
$charlie = new Charlie();
$charlie->bark();


Expected result:
----------------
woof!

Actual result:
--------------
Fatal error: Class Charlie contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (Dog::bark) in Unknown on line 0

If the code is changed so that Charlie extends Dog directly AND the SmallDog class is commented out, the error is:

Fatal error: Call to undefined method Charlie::bark() in /disk1/webs/mydomain/www/test.php on line 13