Changed the sysData cache so that if we didn't fill it in yet, getSysData() returns nil instead of panicking, and the standard window procedure jumps directly to the default handler. Not what I originally wanted to do, but whatever, it finally works!

stdwndclass_windows.go

@@ -16,7 +16,10 @@ var (
 )
 
 func stdWndProc(hwnd _HWND, uMsg uint32, wParam _WPARAM, lParam _LPARAM) _LRESULT {
-//	sysData := getSysData(hwnd)
+	sysData := getSysData(hwnd)
+	if sysData == nil {	// not ready for events yet
+		goto defwndproc
+	}
 	switch uMsg {
 	case _WM_COMMAND:
 		id := wParam.LOWORD()
@@ -32,19 +35,21 @@ func stdWndProc(hwnd _HWND, uMsg uint32, wParam _WPARAM, lParam _LPARAM) _LRESUL
 		// TODO
 		return 0
 	case _WM_CLOSE:
-/*		if sysData.closing != nil {
+		if sysData.closing != nil {
 			sysData.closing <- struct{}{}
 		}
-*/		return 0
+		return 0
 	default:
-		r1, _, _ := defWindowProc.Call(
-			uintptr(hwnd),
-			uintptr(uMsg),
-			uintptr(wParam),
-			uintptr(lParam))
-		return _LRESULT(r1)
+		goto defwndproc
 	}
 	panic(fmt.Sprintf("stdWndProc message %d did not return: internal bug in ui library", uMsg))
+defwndproc:
+	r1, _, _ := defWindowProc.Call(
+		uintptr(hwnd),
+		uintptr(uMsg),
+		uintptr(wParam),
+		uintptr(lParam))
+	return _LRESULT(r1)
 }
 
 type _WNDCLASS struct {

sysdata_windows.go

@@ -38,9 +38,6 @@ var classTypes = [nctypes]*classData{
 }
 
 func (s *sysData) make() (err error) {
-	sysDatasLock.Lock()
-	defer sysDatasLock.Unlock()
-
 	ret := make(chan uiret)
 	defer close(ret)
 	ct := classTypes[s.ctype]

sysdatacache_windows.go

@@ -18,16 +18,18 @@ var (
 	sysDatasLock sync.Mutex
 )
 
-// MUST HAVE LOCKED BEFORE CALLING
 func addSysData(hwnd _HWND, s *sysData) {
+	sysDatasLock.Lock()
+	defer sysDatasLock.Unlock()
 	sysDatas[hwnd] = &sdcEntry{
 		s:			s,
 		members:		map[_HMENU]*sysData{},
 	}
 }
 
-// MUST HAVE LOCKED BEFORE CALLING
 func addIDSysData(hwnd _HWND, id _HMENU, s *sysData) {
+	sysDatasLock.Lock()
+	defer sysDatasLock.Unlock()
 	if ss, ok := sysDatas[hwnd]; ok {
 		ss.members[id] = s
 	}
@@ -40,7 +42,7 @@ func getSysData(hwnd _HWND) *sysData {
 	if ss, ok := sysDatas[hwnd]; ok {
 		return ss.s
 	}
-	panic(fmt.Sprintf("getting nonexistent HWND %d\n", hwnd))
+	return nil
 }
 
 func getIDSysData(hwnd _HWND, id _HMENU) *sysData {