[TYPO3-english] Mount Points and 503 Service Unavailable

[Viktor Livakivskyi]

Hi, List.

I really like idea of Mount Points in TYPO3, but it has one issue, that 
blocks it's usage in production.
Let's imagine such a tree:
root (id=1)
|- section (id=2)
| |- page 1 (id=3)
| |- page 2 (id=4) (mount point to page 3)
|-page 3 (id=5)

I want "page 2" contain contents (and subpages) of "page 3", that's why I 
make it of type "Mount Point" and set "show content of mounted page". So, I 
get a link /index.php?id=5&MP=5-4 at FE in all the menues for "page 2". So 
far so good, but if I try to open "page 2" directly via /index.php?id=4, 
I'll get 503 responce with an exception message. And that it, what I don't 
want FE users to see, if they try to play a little with a website.
At worst case they should see 404 page and at best be redirected 
to /index.php?id=5&MP=5-4, but not some page with an exception message...

Is it expected behaviour of mount points or I'm doing something wrong? Can 
I somehow handle that process, so I can redirect user to 404 page at least?

Thank you in advance.