Index: /trunk/include/VBox/VBoxGuestLib.h
===================================================================
--- /trunk/include/VBox/VBoxGuestLib.h	(revision 84197)
+++ /trunk/include/VBox/VBoxGuestLib.h	(revision 84198)
@@ -947,4 +947,5 @@
 VBGLR3DECL(int) VbglR3GuestCtrlSessionAccept(uint32_t idClient, uint32_t idSession, void const *pvKey, uint32_t cbKey);
 VBGLR3DECL(int) VbglR3GuestCtrlSessionCancelPrepared(uint32_t idClient, uint32_t idSession);
+VBGLR3DECL(int) VbglR3GuestCtrlSessionHasChanged(uint32_t idClient, uint64_t idNewControlSession);
 VBGLR3DECL(int) VbglR3GuestCtrlSessionClose(PVBGLR3GUESTCTRLCMDCTX pCtx, uint32_t fFlags);
 VBGLR3DECL(int) VbglR3GuestCtrlSessionNotify(PVBGLR3GUESTCTRLCMDCTX pCtx, uint32_t uType, int32_t iResult);
Index: /trunk/src/VBox/Additions/common/VBoxGuest/lib/VBoxGuestR3LibGuestCtrl.cpp
===================================================================
--- /trunk/src/VBox/Additions/common/VBoxGuest/lib/VBoxGuestR3LibGuestCtrl.cpp	(revision 84197)
+++ /trunk/src/VBox/Additions/common/VBoxGuest/lib/VBoxGuestR3LibGuestCtrl.cpp	(revision 84198)
@@ -667,4 +667,21 @@
 
 /**
+ * Invalidates the internal state because the (VM) session has been changed (i.e. restored).
+ *
+ * @returns VBox status code.
+ * @param   idClient                Client ID to use for invalidating state.
+ * @param   idNewControlSession     New control session ID. Currently unused.
+ */
+VBGLR3DECL(int) VbglR3GuestCtrlSessionHasChanged(uint32_t idClient, uint64_t idNewControlSession)
+{
+    RT_NOREF(idNewControlSession);
+
+    vbglR3GuestCtrlDetectPeekGetCancelSupport(idClient);
+
+    return VINF_SUCCESS;
+}
+
+
+/**
  * Asks a specific guest session to close.
  *