Ensure that OpenCL device id returned from getDeviceSelection() is valid.

Change-Id: I756bb57d471db3d3ca1d9c3733d359c7c16b4e66
Reviewed-on: https://gerrit.libreoffice.org/24959Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mark Page <aptitude@btconnect.com>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

opencl/source/opencl_device.cxx

@@ -636,10 +636,15 @@ ds_device getDeviceSelection(
         }
 
         /* Final device selection */
-        selectedDevice = aProfile->devices[bestDeviceIdx];
-        bIsDeviceSelected = true;
+        if (bestDeviceIdx >=0 && static_cast< std::vector<ds_device>::size_type> ( bestDeviceIdx ) < aProfile->devices.size() )
+        {
+            selectedDevice = aProfile->devices[bestDeviceIdx];
+            bIsDeviceSelected = true;
 
-        writeDevicesLog(aProfile, sProfilePath, bestDeviceIdx);
+            writeDevicesLog(aProfile, sProfilePath, bestDeviceIdx);
+        } else {
+            selectedDevice.eType = DeviceType::NativeCPU;
+        }
     }
     return selectedDevice;
 }

opencl/source/openclwrapper.cxx

@@ -703,6 +703,8 @@ bool switchOpenCLDevice(const OUString* pDevice, bool bAutoSelect, bool bForceEv
         OUString path;
         osl::FileBase::getSystemPathFromFileURL(url,path);
         ds_device aSelectedDevice = getDeviceSelection(path, bForceEvaluation);
+        if ( aSelectedDevice.eType != DeviceType::OpenCLDevice)
+            return false;
         pDeviceId = aSelectedDevice.aDeviceID;
 
     }