urlmon: Unregister window class on DLL unload.

dlls/urlmon/bindprot.c

@@ -83,14 +83,36 @@ static LRESULT WINAPI notif_wnd_proc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM
     return DefWindowProcW(hwnd, msg, wParam, lParam);
 }
 
+static const WCHAR wszURLMonikerNotificationWindow[] =
+    {'U','R','L',' ','M','o','n','i','k','e','r',' ',
+     'N','o','t','i','f','i','c','a','t','i','o','n',' ','W','i','n','d','o','w',0};
+
+static ATOM notif_wnd_class;
+
+static BOOL WINAPI register_notif_wnd_class(INIT_ONCE *once, void *param, void **context)
+{
+    static WNDCLASSEXW wndclass = {
+        sizeof(wndclass), 0, notif_wnd_proc, 0, 0,
+        NULL, NULL, NULL, NULL, NULL,
+        wszURLMonikerNotificationWindow, NULL
+    };
+
+    wndclass.hInstance = hProxyDll;
+    notif_wnd_class = RegisterClassExW(&wndclass);
+    return TRUE;
+}
+
+void unregister_notif_wnd_class(void)
+{
+    if(notif_wnd_class)
+        UnregisterClassW(MAKEINTRESOURCEW(notif_wnd_class), hProxyDll);
+}
+
 HWND get_notif_hwnd(void)
 {
-    static ATOM wnd_class = 0;
     tls_data_t *tls_data;
 
-    static const WCHAR wszURLMonikerNotificationWindow[] =
-        {'U','R','L',' ','M','o','n','i','k','e','r',' ',
-         'N','o','t','i','f','i','c','a','t','i','o','n',' ','W','i','n','d','o','w',0};
+    static INIT_ONCE init_once = INIT_ONCE_STATIC_INIT;
 
     tls_data = get_tls_data();
     if(!tls_data)
@@ -101,23 +123,11 @@ HWND get_notif_hwnd(void)
         return tls_data->notif_hwnd;
     }
 
-    if(!wnd_class) {
-        static WNDCLASSEXW wndclass = {
-            sizeof(wndclass), 0,
-            notif_wnd_proc, 0, 0,
-            NULL, NULL, NULL, NULL, NULL,
-            wszURLMonikerNotificationWindow,
-            NULL
-        };
-
-        wndclass.hInstance = hProxyDll;
-
-        wnd_class = RegisterClassExW(&wndclass);
-        if (!wnd_class && GetLastError() == ERROR_CLASS_ALREADY_EXISTS)
-            wnd_class = 1;
-    }
+    InitOnceExecuteOnce(&init_once, register_notif_wnd_class, NULL, NULL);
+    if(!notif_wnd_class)
+        return NULL;
 
-    tls_data->notif_hwnd = CreateWindowExW(0, wszURLMonikerNotificationWindow,
+    tls_data->notif_hwnd = CreateWindowExW(0, MAKEINTRESOURCEW(notif_wnd_class),
             wszURLMonikerNotificationWindow, 0, 0, 0, 0, 0, HWND_MESSAGE,
             NULL, hProxyDll, NULL);
     if(tls_data->notif_hwnd)

dlls/urlmon/urlmon_main.c

@@ -139,6 +139,7 @@ static void process_detach(void)
 
     free_session();
     free_tls_list();
+    unregister_notif_wnd_class();
 }
 
 /***********************************************************************

dlls/urlmon/urlmon_main.h

@@ -225,6 +225,7 @@ typedef struct {
 
 tls_data_t *get_tls_data(void) DECLSPEC_HIDDEN;
 
+void unregister_notif_wnd_class(void) DECLSPEC_HIDDEN;
 HWND get_notif_hwnd(void) DECLSPEC_HIDDEN;
 void release_notif_hwnd(HWND) DECLSPEC_HIDDEN;