Corrects invalid read access from the MacOsX/Windows libjitsi coreaudio...

Corrects invalid read access from the MacOsX/Windows libjitsi coreaudio library when creating or receiving a call without any microphone connected.

src/org/jitsi/impl/neomedia/maccoreaudio/CoreAudioVolumeControl.java

@@ -51,6 +51,11 @@ public CoreAudioVolumeControl(
      */
     protected int setInputDeviceVolume(String deviceUID, float volume)
     {
+        if(deviceUID == null)
+        {
+            return -1;
+        }
+
         // Changes the input volume of the capture device.
         if(CoreAudioDevice.setInputDeviceVolume(deviceUID, volume) != 0)
         {
@@ -71,6 +76,11 @@ protected int setInputDeviceVolume(String deviceUID, float volume)
      */
     protected float getInputDeviceVolume(String deviceUID)
     {
+        if(deviceUID == null)
+        {
+            return -1;
+        }
+
         float volume = CoreAudioDevice.getInputDeviceVolume(deviceUID);
 
         if(logger.isDebugEnabled() && (volume != 0))

src/org/jitsi/impl/neomedia/wincoreaudio/CoreAudioVolumeControl.java

@@ -51,6 +51,11 @@ public CoreAudioVolumeControl(
      */
     protected int setInputDeviceVolume(String deviceUID, float volume)
     {
+        if(deviceUID == null)
+        {
+            return -1;
+        }
+
         if(CoreAudioDevice.initDevices() == -1)
         {
             CoreAudioDevice.freeDevices();
@@ -83,6 +88,11 @@ protected float getInputDeviceVolume(String deviceUID)
     {
         float volume;
 
+        if(deviceUID == null)
+        {
+            return -1;
+        }
+
         if(CoreAudioDevice.initDevices() == -1)
         {
             CoreAudioDevice.freeDevices();