Fix merging of weight systems

[Linus Torvalds]

On Mon, Oct 29, 2012 at 11:36 AM, Dirk Hohndel <dirk at hohndel.org> wrote:
>
> Turns out that on the Uemis you can add weight information on the dive
> computer and we can indeed parse that from Subsurface. So there it is
> entirely possible (even likely) that you have manually entered weight
> info with the correct weight description, yet you get weight info from
> the computer on a new download with description "unknown". I think the
> right thing to do is:
>
> if both have weight info
>   if the total weight is the same
>     keep the one that doesn't have "unknown" as description
>
> All other cases: accumulate all of the weight info from both "dives"

Right now, it prefers the older version if there's any weight
information there. So that should work too for the Uemis import case.
But yeah, we could have some "fill in from both dives" model too.

         Linus