Cylinders: access cylinders with get_cylinder()

Instead of accessing the cylinder table directly, use the get_cylinder()
function. This gives less unwieldy expressions. But more importantly,
the function does bound checking. This is crucial for now as the code
hasn't be properly audited since the change to arbitrarily sized
cylinder tables. Accesses of invalid cylinder indexes may lead to
silent data-corruption that is sometimes not even noticed by
valgrind. Returning NULL instead of an invalid pointer will make
debugging much easier.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/qt-models/models.cpp b/qt-models/models.cpp
index ab80f95f0..7be9c2440 100644
--- a/qt-models/models.cpp
+++ b/qt-models/models.cpp
@@ -27,7 +27,7 @@ static QStringList getGasList()
 {
 	QStringList list;
 	for (int i = 0; i < displayed_dive.cylinders.nr; i++) {
-		const cylinder_t *cyl = &displayed_dive.cylinders.cylinders[i];
+		const cylinder_t *cyl = get_cylinder(&displayed_dive, i);
 		/* Check if we have the same gasmix two or more times
 		 * If yes return more verbose string */
 		int same_gas = same_gasmix_cylinder(cyl, i, &displayed_dive, true);