Undo: remember deleted trip in UndoRemoveDivesFromTrip::undo()

If the last dive of a trip is removed, the trip is deleted.
On redo the dive is added to a non existing trip, leading to a
segfault.

Therefore, keep a copy of the trip to reinstate it on redo.
Note: this cannot work for a sequence of multiple commands.
One would have to rewrite the whole undo-history. Nevertheless,
let's do this as a stop-gap measure.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

1 files changed, 13 insertions, 0 deletions

diff --git a/core/divelist.c b/core/divelist.c
index 7291de23e..a9b793517 100644
--- a/core/divelist.c
+++ b/core/divelist.c
@@ -727,6 +727,19 @@ void insert_trip(dive_trip_t **dive_trip_p)
 #endif
 }
 
+/* create a copy of a dive trip, but don't add any dives. */
+dive_trip_t *clone_empty_trip(dive_trip_t *trip)
+{
+	dive_trip_t *copy = malloc(sizeof(struct dive_trip));
+	*copy = *trip;
+	copy->location = copy_string(trip->location);
+	copy->notes = copy_string(trip->notes);
+	copy->nrdives = 0;
+	copy->next = NULL;
+	copy->dives = NULL;
+	return copy;
+}
+
 static void delete_trip(dive_trip_t *trip)
 {
 	dive_trip_t **p, *tmp;