A null pointer dereference occured after right click on a dive trip
because updateDiveInfo was called with dive == -1 causing get_dive(int)
to return null.
Wrap to avoid crash and clear dive info widget text labels.
[Dirk Hohndel: this is different from the fix I had committed earlier;
I decided to combine the ideas, clean this one up a bit
more and this is the result]
Signed-off-by: Amit Chaudhuri <amit.k.chaudhuri@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
b5d5b05140