Planner: don't do unnecessary work on empty dive plans

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

3 files changed, 18 insertions, 1 deletions

diff --git a/planner.c b/planner.c
index 2cc47258c..405b07e02 100644
--- a/planner.c
+++ b/planner.c
@@ -49,6 +49,20 @@ void dump_plan(struct diveplan *diveplan)
 }
 #endif
 
+bool diveplan_empty(struct diveplan *diveplan)
+{
+	struct divedatapoint *dp;
+	if (!diveplan || !diveplan->dp)
+		return true;
+	dp = diveplan->dp;
+	while(dp) {
+		if (dp->time)
+			return false;
+		dp = dp->next;
+	}
+	return true;
+}
+
 void set_last_stop(bool last_stop_6m)
 {
 	if (last_stop_6m == true)
diff --git a/planner.h b/planner.h
index 49f8be5ef..d5607a948 100644
--- a/planner.h
+++ b/planner.h
@@ -13,6 +13,7 @@ extern void show_planned_dive(char **error_string_p);
 extern void set_last_stop(bool last_stop_6m);
 extern void get_gas_from_events(struct divecomputer *dc, int time, int *o2, int *he);
 extern int get_gasidx(struct dive *dive, int o2, int he);
+extern bool diveplan_empty(struct diveplan *diveplan);
 
 extern struct dive *planned_dive;
 extern char *cache_data;
diff --git a/qt-ui/diveplanner.cpp b/qt-ui/diveplanner.cpp
index 2b1662f7d..0d5b79edd 100644
--- a/qt-ui/diveplanner.cpp
+++ b/qt-ui/diveplanner.cpp
@@ -777,6 +777,8 @@ void DivePlannerPointsModel::addDecoToModel()
 {
 	struct divedatapoint *dp;
 
+	if (diveplan_empty(&diveplan))
+		return;
 	bool oldRecalc = plannerModel->setRecalc(false);
 	plannerModel->removeDeco();
 
@@ -832,7 +834,7 @@ void DivePlannerPointsModel::createTemporaryPlan()
 #if DEBUG_PLAN
 	dump_plan(&diveplan);
 #endif
-	if (plannerModel->recalcQ()) {
+	if (plannerModel->recalcQ() && !diveplan_empty(&diveplan)) {
 		plan(&diveplan, &cache, &tempDive, stagingDive, isPlanner());
 		addDecoToModel();
 		if (mode == ADD || mode == PLAN) {