Fix windows crash

Author: Ximi1970

src/modules/winnt/FiretrayWindow.jsm

@@ -131,13 +131,21 @@ firetray.Window.wndProcStartup = function(hWnd, uMsg, wParam, lParam) {
   return user32.CallWindowProcW(user32.WNDPROC(procPrev), hWnd, uMsg, wParam, lParam);
 };
 
+// https://social.msdn.microsoft.com/Forums/en-US/4eb3bad0-caf3-45ca-bfe8-7bc257af986a/getwindowlongsetwindowlong-on-gwlwndproc-crashes-in-compact-2013?forum=winembmngdapp
+var procNat = null;
+firetray.Window.NativeWndProc = function(hWnd, uMsg, wParam, lParam) {
+  return user32.CallWindowProcW(user32.WNDPROC(procNat), hWnd, uMsg, wParam, lParam);
+}
+
 // procInfo = {wid, hwnd, jsProc, mapNew, mapBak}
 firetray.Window.attachWndProc = function(procInfo) {
   try {
     let wndProc = ctypes.cast(user32.WNDPROC(procInfo.jsProc), win32.LONG_PTR);
     log.debug("proc="+wndProc);
     procInfo.mapNew.insert(procInfo.wid, wndProc);
-    let procPrev = user32.SetWindowLongW(procInfo.hwnd, user32.GWLP_WNDPROC, wndProc);
+//    let procPrev = user32.SetWindowLongW(procInfo.hwnd, user32.GWLP_WNDPROC, wndProc);
+    this.procNat = wndProc;
+    let procPrev = user32.SetWindowLongW(procInfo.hwnd, user32.GWLP_WNDPROC, this.procNat);
     log.debug("procPrev="+procPrev+" winLastError="+ctypes.winLastError);
     /* we can't store WNDPROC callbacks (JS ctypes objects) with SetPropW(), as
      we need long-living refs. */