wrong strpos() check in Doctrine_Cache_Driver::deleteByPrefix()

In Doctrine_Cache_Driver::::deleteByPrefix() on line 216 you can read:

if (strpos($key, $prefix) == 0) ...

to check whether the prefix starts on the first position.
As strpos() returns false if the prefix is not found at all and 0 evaluates to false this results to the deletion of unnecessary cache keys.

correct would be:

if (strpos($key, $prefix) === 0) ... // triple '='