[PATCH] Check if trip is NULL before calling DIVE_TRIP

[Dirk Hohndel]

"Lubomir I. Ivanov" <neolit123 at gmail.com> writes:

> right, it crashes because of this file's trip date (attribute in <trip> tag):
>
> <trip date='2011-12-02
> if changed to:
> <trip date='2012-12-02'
> all is good.

Yeah, with this we have to trips on the same date with different
times. That shouldn't cause any issues but clearly it does.

But this definitely provides enough information to step through it and
figure it out.

/D