Bug ID domain?

[Gervase Markham]

> What is the domain of possible values for bug IDs?  I get the idea that IDs
> are positive integers, but is this codified somewhere?

Well, currently they are auto-allocated by the database, starting at 1 
and going upwards, so it's codified like that. The domain is 1 -> 2^31 
at least.

> ...I'd like to use a special bug_id to store the default value for a given
> field_id.  NULL is out, unfortunately, because I need that primary key.
> Would using a number like 0 or -1 be safe?

Both would probably be safe, but I think bbaetz normally has things to 
say about hacks like this...

Gerv