internal server error when adding a new user with incorrect password guidelines

[oremj]

Moved from Bug 1454334.

I was trying to add a new account for our very own RelEng Simon Fraser (sfarser) and bouncer failed me twice with "internal server error". I tried different passwords and eventually I managed to get passed through. After successful addition I've noticed there's a "Required. 30 characters or fewer. Letters, digits and @/./+/-/_ only." guideline.

Would be nice if bouncer did a better job at handling that error and throw an "form input error for password" or so rather than internal server error.