Index: /trunk/src/VBox/Additions/common/VBoxGuestLib/VBoxGuestR0LibCrOgl.cpp
===================================================================
--- /trunk/src/VBox/Additions/common/VBoxGuestLib/VBoxGuestR0LibCrOgl.cpp	(revision 50820)
+++ /trunk/src/VBox/Additions/common/VBoxGuestLib/VBoxGuestR0LibCrOgl.cpp	(revision 50821)
@@ -92,7 +92,16 @@
     rc = vbglDriverIOCtl (&hCtl->driver, VBOXGUEST_IOCTL_HGCM_CONNECT, &info, sizeof (info));
     if (RT_SUCCESS(rc))
-        *pu32ClientID = info.u32ClientID;
-    else
-        *pu32ClientID = 0;
+    {
+        rc = info.result;
+        if (RT_SUCCESS(rc))
+        {
+            Assert(info.u32ClientID);
+            *pu32ClientID = info.u32ClientID;
+            return rc;
+        }
+    }
+
+    Assert(RT_FAILURE(rc));
+    *pu32ClientID = 0;
     return rc;
 }