ntdll/tests: Fix a crash on some Vista boxes.

dlls/ntdll/tests/reg.c

@@ -735,6 +735,8 @@ static void test_symlinks(void)
         "wrong len %u\n", len );
     pNtClose( key );
 
+    if (0)  /* crashes the Windows kernel on some Vista systems */
+    {
         /* reopen the link from itself */
 
         attr.RootDirectory = link;
@@ -757,10 +759,13 @@ static void test_symlinks(void)
         ok( len == FIELD_OFFSET(KEY_VALUE_PARTIAL_INFORMATION,Data) + target_len - sizeof(WCHAR),
             "wrong len %u\n", len );
         pNtClose( key );
+    }
 
     if (0)  /* crashes the Windows kernel in most versions */
     {
+        attr.RootDirectory = link;
         attr.Attributes = 0;
+        attr.ObjectName = &null_str;
         status = pNtOpenKey( &key, KEY_ALL_ACCESS, &attr );
         ok( status == STATUS_SUCCESS, "NtOpenKey failed: 0x%08x\n", status );
         len = sizeof(buffer);