[PATCH] Add some gas mix validation to the planner

[Rick Walsh]

A few basic rules for gas validation:
	We can't have <0%, or >100% of either O2 or He
	O2 + He must not be >100%
	Switch depth can't be <0%

This places limits on user-input values

Signed-off-by: Rick Walsh <rickmwalsh at gmail.com>
---
 core/qthelper.cpp           | 9 +++++++++
 qt-models/cylindermodel.cpp | 6 ++++++
 2 files changed, 15 insertions(+)

diff --git a/core/qthelper.cpp b/core/qthelper.cpp
index 24c51d2..d6a6c25 100644
--- a/core/qthelper.cpp
+++ b/core/qthelper.cpp
@@ -1253,6 +1253,8 @@ depth_t string_to_depth(const char *str)
 	QString local_m = QObject::tr("m");
 	depth_t depth;
 
+	if (value < 0)
+		value = 0;
 	if (rest.startsWith("m") || rest.startsWith(local_m))
 		goto m;
 	if (rest.startsWith("ft") || rest.startsWith(local_ft))
@@ -1328,6 +1330,13 @@ fraction_t string_to_fraction(const char *str)
 	fraction_t fraction;
 
 	fraction.permille = rint(value * 10);
+	/*
+	 * Don't permit values less than zero or greater than 100%
+	 */
+	if (fraction.permille < 0)
+		fraction.permille = 0;
+	else if (fraction.permille > 1000)
+		fraction.permille = 1000;
 	return fraction;
 }
 
diff --git a/qt-models/cylindermodel.cpp b/qt-models/cylindermodel.cpp
index 1ad03f9..20b7207 100644
--- a/qt-models/cylindermodel.cpp
+++ b/qt-models/cylindermodel.cpp
@@ -249,6 +249,9 @@ bool CylindersModel::setData(const QModelIndex &index, const QVariant &value, in
 	case O2:
 		if (CHANGED()) {
 			cyl->gasmix.o2 = string_to_fraction(vString.toUtf8().data());
+			// fO2 + fHe must not be greater than 1
+			if (((cyl->gasmix.o2.permille == 0) ? O2_IN_AIR : cyl->gasmix.o2.permille) + cyl->gasmix.he.permille > 1000)
+				cyl->gasmix.he.permille = 1000 - ((cyl->gasmix.o2.permille == 0) ? O2_IN_AIR : cyl->gasmix.o2.permille);
 			pressure_t modpO2;
 			if (displayed_dive.dc.divemode == PSCR)
 				modpO2.mbar = prefs.decopo2 + (1000 - get_o2(&cyl->gasmix)) * SURFACE_PRESSURE *
@@ -262,6 +265,9 @@ bool CylindersModel::setData(const QModelIndex &index, const QVariant &value, in
 	case HE:
 		if (CHANGED()) {
 			cyl->gasmix.he = string_to_fraction(vString.toUtf8().data());
+			// fO2 + fHe must not be greater than 1
+			if (((cyl->gasmix.o2.permille == 0) ? O2_IN_AIR : cyl->gasmix.o2.permille) + cyl->gasmix.he.permille > 1000)
+				cyl->gasmix.o2.permille = 1000 - cyl->gasmix.he.permille;
 			changed = true;
 		}
 		break;
-- 
2.5.5