Add some better error handling to the WMDM device lister if parts of WMP aren't installed

src/devices/wmdmdevice.cpp

@@ -73,6 +73,8 @@ bool WmdmDevice::StartCopy(QList<Song::FileType>* supported_types) {
 
   // This initialises COM and gets a connection to the device
   thread_.reset(new WmdmThread);
+  if (!thread_->manager())
+    return false;
 
   // Find a place to put the files.  We default to the root folder for now, but
   // could look for a "Music" folder in the future?

src/devices/wmdmlister.cpp

@@ -55,6 +55,8 @@ WmdmLister::~WmdmLister() {
 
 void WmdmLister::Init() {
   thread_.reset(new WmdmThread);
+  if (!thread_->manager())
+    return;
 
   // Register for notifications
   IConnectionPointContainer* cp_container = NULL;

src/devices/wmdmthread.cpp

@@ -29,7 +29,8 @@ BYTE abCert[] = {0x00};
 
 
 WmdmThread::WmdmThread()
-  : device_manager_(NULL)
+  : device_manager_(NULL),
+    sac_(NULL)
 {
   // Initialise COM
   CoInitialize(0);
@@ -63,11 +64,15 @@ WmdmThread::WmdmThread()
 }
 
 WmdmThread::~WmdmThread() {
+  if (device_manager_) {
     // Release the device manager
     device_manager_->Release();
+  }
 
+  if (sac_) {
     // SAC
     CSecureChannelClient_Free(sac_);
+  }
 
   // Uninitialise COM
   CoUninitialize();