Don't update cached char value when property is not readable

In addition we update the documentation to reflect the slightly changed
API behavior.

Change-Id: Ieddee750aa35a32d3c01213dfbf678ee2a1d88d7
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/src/bluetooth/qlowenergycontroller_android.cpp b/src/bluetooth/qlowenergycontroller_android.cpp
index 9be5cff0..e1b668ca 100644
--- a/src/bluetooth/qlowenergycontroller_android.cpp
+++ b/src/bluetooth/qlowenergycontroller_android.cpp
@@ -431,7 +431,10 @@ void QLowEnergyControllerPrivate::characteristicWritten(
         return;
     }
 
-    updateValueOfCharacteristic(charHandle, data, false);
+    // only update cache when property is readable. Otherwise it remains
+    // empty.
+    if (characteristic.properties() & QLowEnergyCharacteristic::Read)
+        updateValueOfCharacteristic(charHandle, data, false);
     emit service->characteristicWritten(characteristic, data);
 }
 
@@ -479,7 +482,10 @@ void QLowEnergyControllerPrivate::characteristicChanged(
         return;
     }
 
-    updateValueOfCharacteristic(characteristic.attributeHandle(),
+    // only update cache when property is readable. Otherwise it remains
+    // empty.
+    if (characteristic.properties() & QLowEnergyCharacteristic::Read)
+        updateValueOfCharacteristic(characteristic.attributeHandle(),
                                 data, false);
     emit service->characteristicChanged(characteristic, data);
 }