Android: don't crash if Gravity is not supported

The QtSensors documentation says that if Gravity mode is not available,
we should silently fall back to the default Combined mode.

In addition, add null pointer checks in case we try to ask for non-existent
sensors in the future.

Task-number: QTBUG-39335
Change-Id: I6c18622d081db4e3a7d07c744bb0b746e3f5c6ff
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>

3 files changed, 8 insertions, 0 deletions

diff --git a/src/plugins/sensors/android/jar/src/org/qtproject/qt5/android/sensors/QtSensors.java b/src/plugins/sensors/android/jar/src/org/qtproject/qt5/android/sensors/QtSensors.java
index 5507b07..efd1ff6 100644
--- a/src/plugins/sensors/android/jar/src/org/qtproject/qt5/android/sensors/QtSensors.java
+++ b/src/plugins/sensors/android/jar/src/org/qtproject/qt5/android/sensors/QtSensors.java
@@ -73,6 +73,9 @@ public class QtSensors implements SensorEventListener
     {
         try {
             Sensor s  = m_sensorManager.getDefaultSensor(sensorType);
+            if (s == null) {
+                return null;
+            }
             return s.getName() + " " + s.getVendor() + " v" + s.getVersion();
         } catch(Exception e) {
             e.printStackTrace();
diff --git a/src/plugins/sensors/android/src/androidaccelerometer.cpp b/src/plugins/sensors/android/src/androidaccelerometer.cpp
index 76aa027..74b3d6d 100644
--- a/src/plugins/sensors/android/src/androidaccelerometer.cpp
+++ b/src/plugins/sensors/android/src/androidaccelerometer.cpp
@@ -95,5 +95,8 @@ AndroidSensors::AndroidSensorType AndroidAccelerometer::modeToSensor(QAccelerome
         break;
     }
 
+    if (type != AndroidSensors::TYPE_ACCELEROMETER && !AndroidSensors::availableSensors().contains(type))
+        type = AndroidSensors::TYPE_ACCELEROMETER;
+
     return type;
 }
diff --git a/src/plugins/sensors/android/src/androidjnisensors.cpp b/src/plugins/sensors/android/src/androidjnisensors.cpp
index af39e0b..87889a8 100644
--- a/src/plugins/sensors/android/src/androidjnisensors.cpp
+++ b/src/plugins/sensors/android/src/androidjnisensors.cpp
@@ -113,6 +113,8 @@ namespace AndroidSensors
         jstring jstr = static_cast<jstring>(aenv.jniEnv->CallStaticObjectMethod(sensorsClass,
                                                                                 getSensorDescriptionMethodId,
                                                                                 jint(sensor)));
+        if (!jstr)
+            return QString();
         const jchar *pstr = aenv.jniEnv->GetStringChars(jstr, 0);
         QString ret(reinterpret_cast<const QChar *>(pstr), aenv.jniEnv->GetStringLength(jstr));
         aenv.jniEnv->ReleaseStringChars(jstr, pstr);