Description:
------------
When calling opendir, PHP segfaults.

Reproduce code:
---------------
<?
class mystream {
    function stream_open($path, $mode, $options, &$opened_path) {
        return true;
    }

    function dir_opendir($url, $options) {
        return true;
    }
}

if(!stream_wrapper_register("test", "mystream"))
{
    die("test wrapper registration failed");
}

mkdir("test://a");
$dir = opendir("test://a");     // The SEGV happens here

?>


Expected result:
----------------
PHP should not crash.

Actual result:
--------------
(gdb) run
Starting program: /home/angio/php-5.1.4/sapi/cli/php ~/test.php

Warning: mkdir(): mystream::mkdir is not implemented! in /home/angio/test.php on line 19

Program received signal SIGSEGV, Segmentation fault.
0x0824e632 in zend_object_store_get_object (zobject=0x3)
    at /home/angio/php-5.1.4/Zend/zend_objects_API.c:215
215             return EG(objects_store).object_buckets[handle].bucket.obj.object;
(gdb) t
[Current thread is 0 (process 28095)]
(gdb) where
#0  0x0824e632 in zend_object_store_get_object (zobject=0x3)
    at /home/angio/php-5.1.4/Zend/zend_objects_API.c:215
#1  0x08225030 in zend_call_function (fci=0xbfb6c270, fci_cache=0x0)
    at /home/angio/php-5.1.4/Zend/zend_execute_API.c:661
#2  0x0822524e in call_user_function_ex (function_table=0x3, object_pp=0x3,
    function_name=0x3, retval_ptr_ptr=0x3, param_count=3, params=0x3,
    no_separation=3, symbol_table=0x3)
    at /home/angio/php-5.1.4/Zend/zend_execute_API.c:579
#3  0x082095bf in php_userstreamop_closedir (stream=0x3, close_handle=1)
    at /home/angio/php-5.1.4/main/streams/userspace.c:1266
#4  0x082009d4 in _php_stream_free (stream=0x842a43c, close_options=11)
    at /home/angio/php-5.1.4/main/streams/streams.c:342
#5  0x0820129c in stream_resource_regular_dtor (rsrc=0x3)
    at /home/angio/php-5.1.4/main/streams/streams.c:1373
#6  0x0823e8bf in list_entry_destructor (ptr=0x842c634)
    at /home/angio/php-5.1.4/Zend/zend_list.c:184
#7  0x0823d2ba in zend_hash_apply_deleter (ht=0x8374bc0, p=0x842c954)
    at /home/angio/php-5.1.4/Zend/zend_hash.c:576
#8  0x0823d387 in zend_hash_graceful_reverse_destroy (ht=0x8374bc0)
    at /home/angio/php-5.1.4/Zend/zend_hash.c:642
#9  0x0823165e in zend_deactivate () at /home/angio/php-5.1.4/Zend/zend.c:860
#10 0x081ec005 in php_request_shutdown (dummy=0x0)
    at /home/angio/php-5.1.4/main/main.c:1287
---Type <return> to continue, or q <return> to quit---
#11 0x082b34db in main (argc=2, argv=0xbfb6cfb4)
    at /home/angio/php-5.1.4/sapi/cli/php_cli.c:1245
(gdb)