[PATCH] Air isn't special

[subsurface at henrik.synth.no]

From: Henrik Brautaset Aronsen <subsurface at henrik.synth.no>

The notion that air is special is a weird one.  It clutters our code
base with special handling whenever o2 == 0 means AIR.  (All my rec
dives are with EAN32.  Why can't that be special instead? ;)

The only reason I see to treat air special is to leave out o2=21.0
in the dive log xml.  So let's do it there instead (not included here).

Signed-off-by: Henrik Brautaset Aronsen <subsurface at henrik.synth.no>
---
 dive.c                | 13 ++++---------
 planner.c             |  3 ---
 qt-ui/diveplanner.cpp |  2 +-
 3 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/dive.c b/dive.c
index 0d8f487..4e7a684 100644
--- a/dive.c
+++ b/dive.c
@@ -527,15 +527,10 @@ void sanitize_gasmix(struct gasmix *mix)
 	o2 = mix->o2.permille;
 	he = mix->he.permille;
 
-	/* Regular air: leave empty */
-	if (!he) {
-		if (!o2)
-			return;
-		/* 20.8% to 21% O2 is just air */
-		if (is_air(o2, he)) {
-			mix->o2.permille = 0;
-			return;
-		}
+	/* Regular air: */
+	if (!he && !o2) {
+		mix->o2.permille = O2_IN_AIR;
+		return;
 	}
 
 	/* Sane mix? */
diff --git a/planner.c b/planner.c
index f062ee6..887a955 100644
--- a/planner.c
+++ b/planner.c
@@ -93,9 +93,6 @@ int get_gasidx(struct dive *dive, int o2, int he)
 	mix.o2.permille = o2;
 	mix.he.permille = he;
 
-	/* we treat air as 0/0 because it is special */
-	//if (is_air(o2, he))
-	//	o2 = 0;
 	while (++gasidx < MAX_CYLINDERS)
 		if (gasmix_distance(&dive->cylinder[gasidx].gasmix, &mix) < 200)
 			return gasidx;
diff --git a/qt-ui/diveplanner.cpp b/qt-ui/diveplanner.cpp
index 252c0ff..1d454ea 100644
--- a/qt-ui/diveplanner.cpp
+++ b/qt-ui/diveplanner.cpp
@@ -528,7 +528,7 @@ bool DivePlannerPointsModel::addGas(int o2, int he)
 	sanitize_gasmix(&mix);
 
 	if (is_air(o2, he))
-		o2 = 0;
+		o2 = O2_IN_AIR;
 
 	for (int i = 0; i < MAX_CYLINDERS; i++) {
 		cylinder_t *cyl = &stagingDive->cylinder[i];
-- 
1.8.5.2 (Apple Git-48)