[PATCH] Check if trip is NULL before calling DIVE_TRIP

[Lubomir I. Ivanov]

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

Other places have this check, but for this particular one a crash
can be reproduced:

./subsurface ./dives/*
log -> autogroup
log -> autogroup

Against d14932058f191de2a

Signed-off-by: Lubomir I. Ivanov <neolit123 at gmail.com>
---
 divelist.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/divelist.c b/divelist.c
index f032e62..909e27b 100644
--- a/divelist.c
+++ b/divelist.c
@@ -1067,7 +1067,8 @@ static void fill_dive_list(void)
 			}
 		} else if (DIVE_IN_TRIP(dive)) {
 			trip = find_matching_trip(dive->when);
-			dive_trip = DIVE_TRIP(trip);
+			if (trip)
+				dive_trip = DIVE_TRIP(trip);
 		} else {
 			/* dive is not in a trip and we aren't autogrouping */
 			dive_trip = NULL;
-- 
1.7.11.msysgit.0