Don't walk back in time

A strange and buggy dive where time goes backwards (right now easy to
create with the dive plan editor) can cause us to run out of plot info
elements.

This prevents that from causing memory corruption by refusing to go back
in time.

Reported-by: Dirk Hohndel <dirk@hohndel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/profile.c b/profile.c
index f9cb78a17..c1603c377 100644
--- a/profile.c
+++ b/profile.c
@@ -1640,6 +1640,10 @@ static struct plot_data *populate_plot_entries(struct dive *dive, struct divecom
 
 		/* Add intermediate plot entries if required */
 		delta = time - lasttime;
+		if (delta < 0) {
+			time = lasttime;
+			delta = 0;
+		}
 		for (offset = 10; offset < delta; offset += 10) {
 			if (lasttime + offset > maxtime)
 				break;