hw/xwin: Always set the X input focus to none when an X window loses focus

In the multiwindow WM, we need to cancel the X input focus if the
Windows input focus has gone to the desktop, or another application's
window.

We could maybe avoid some unneeded work by not doing this if the
WM_KILLFOCUS wParam is another window owned by us, which is immediately
going to be given the X input focus.

Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/736>

hw/xwin/winmultiwindowwm.c

@@ -905,6 +905,7 @@ winMultiWindowWMProc(void *pArg)
                -- independently, the WM_TAKE_FOCUS protocol determines whether
                the WM should send a WM_TAKE_FOCUS ClientMessage.
             */
+            if (pNode->msg.iWindow)
             {
               Bool neverFocus = FALSE;
               xcb_get_property_cookie_t cookie;
@@ -928,6 +929,13 @@ winMultiWindowWMProc(void *pArg)
                              pNode->msg.iWindow,
                              pWMInfo->atmWmProtos, pWMInfo->atmWmTakeFocus);
 
+            }
+            else
+            /* Set the input focus to none */
+            {
+              xcb_set_input_focus(pWMInfo->conn, XCB_INPUT_FOCUS_NONE,
+                                  XCB_NONE, XCB_CURRENT_TIME);
+
             }
             break;
 

hw/xwin/winmultiwindowwndproc.c

@@ -808,9 +808,13 @@ winTopLevelWindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
         /* Remove our keyboard hook if it is installed */
         winRemoveKeyboardHookLL();
 
-        /* Revert the X focus as well, but only if the Windows focus is going to another window */
+        /* Revert the X focus as well */
-        if (!wParam && pWin)
+        if (fWMMsgInitialized)
-            DeleteWindowFromAnyEvents(pWin, FALSE);
+            {
+                wmMsg.msg = WM_WM_ACTIVATE;
+                wmMsg.iWindow = 0;
+                winSendMessageToWM(s_pScreenPriv->pWMInfo, &wmMsg);
+            }
 
         return 0;