Re: ordered indexing for integers

[Howard Chu <hyc@symas.com>]

Hallvard B Furuseth wrote:
> Also overflow gives wrong ordering:
>     value 0x100000000: index 0480000000
>     value  0x80000000: index 0580800000
> I'm too tired to figure out what the code does at overflow now, and
> maybe I misunderstood the discussion earlier, but it should give the
> right _ordering_ for overflow even if it can't make a very exact index.

Right. All fixed.

> I wrote:
> > To get the correct ordering, use normal (fully sign-extended) two's
> > complement but with the sign bit inversed.  (Same as value + max
> > positive value + 1)

The sign bit was already being handled, but I was zero-extending instead of 
sign-extending. (doh...)

> Actually, looking at lutil_str2bin() one's complement would be easier:-)

It might have been, but the current 2's complement is BER-compatible.

> And maybe it needs to turn '-0' into '0'?  I think that's invalid LDAP
> Integer syntax so it doesn't matter in that context, but still.

Right, invalid; integerValidate will reject it so it'll never get here.

--
  -- Howard Chu
  Chief Architect, Symas Corp.  http://www.symas.com
  Director, Highland Sun        http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP     http://www.openldap.org/project/