PS. Actually my PHP version is 5.3.5

Fixed version and OS

Actually, there is no `default constructor` in PHP, you should decalare one be 
fore you call to it. 
I think this should be mark as a feature request.

Well you can call:

$base = new Base();

which works, because php uses default, empty constructor.
If new operator can call it, why derived classes can't?

yes, you can instantiate a calss without a constructor be declared, but that doesn't mean there is default empty constructor. 

in PHP, constructor most like a magic method which will be called after a object instantiated immediatlely. 
 
so if there is no constructor for a class, the new operator still can instantiate a class. but you can't call a no-exists constructor directly :)

I stand by my request because of cohesion.
I often see useless code in derived classes, e.g.:

function __construct($name) {
    parent::__construct($name);
}

which does absolutely nothing and I delete this code, because php will do it 
automatically.
For the same reason I'd like to remove

function __construct() {
    ;
}

which also does absolutely nothing and php will do the same automatically EXCEPT 
in the case I described.

So, I stand by my request :)

> So, I stand by my request :)

Apparently, nobody else does.  So if you're still interested in
this, please forward the request to the internals mailing list.
For the time being, I'm suspending this ticket.