explorer: Call user driver through a new CreateDesktop callback.

dlls/user32/winstation.c

@@ -256,7 +256,7 @@ HDESK WINAPI CreateDesktopW( LPCWSTR name, LPCWSTR device, LPDEVMODEW devmode,
     OBJECT_ATTRIBUTES attr;
     UNICODE_STRING str;
 
-    if (device || devmode)
+    if (device || (devmode && !(flags & DF_WINE_CREATE_DESKTOP)))
     {
         SetLastError( ERROR_INVALID_PARAMETER );
         return 0;

dlls/win32u/driver.c

@@ -783,6 +783,11 @@ static BOOL nulldrv_UpdateDisplayDevices( const struct gdi_device_manager *manag
     return FALSE;
 }
 
+static BOOL nulldrv_CreateDesktop( const WCHAR *name, UINT width, UINT height )
+{
+    return TRUE;
+}
+
 static BOOL nodrv_CreateWindow( HWND hwnd )
 {
     static int warned;
@@ -1149,6 +1154,11 @@ static BOOL loaderdrv_UpdateDisplayDevices( const struct gdi_device_manager *man
     return load_driver()->pUpdateDisplayDevices( manager, force, param );
 }
 
+static BOOL loaderdrv_CreateDesktop( const WCHAR *name, UINT width, UINT height )
+{
+    return load_driver()->pCreateDesktop( name, width, height );
+}
+
 static BOOL loaderdrv_CreateWindow( HWND hwnd )
 {
     return load_driver()->pCreateWindow( hwnd );
@@ -1222,6 +1232,7 @@ static const struct user_driver_funcs lazy_load_driver =
     loaderdrv_GetDisplayDepth,
     loaderdrv_UpdateDisplayDevices,
     /* windowing functions */
+    loaderdrv_CreateDesktop,
     loaderdrv_CreateWindow,
     nulldrv_DesktopWindowProc,
     nulldrv_DestroyWindow,
@@ -1300,6 +1311,7 @@ void __wine_set_user_driver( const struct user_driver_funcs *funcs, UINT version
     SET_USER_FUNC(GetCurrentDisplaySettings);
     SET_USER_FUNC(GetDisplayDepth);
     SET_USER_FUNC(UpdateDisplayDevices);
+    SET_USER_FUNC(CreateDesktop);
     SET_USER_FUNC(CreateWindow);
     SET_USER_FUNC(DesktopWindowProc);
     SET_USER_FUNC(DestroyWindow);

dlls/win32u/winstation.c

@@ -141,9 +141,10 @@ HDESK WINAPI NtUserCreateDesktopEx( OBJECT_ATTRIBUTES *attr, UNICODE_STRING *dev
                                     DEVMODEW *devmode, DWORD flags, ACCESS_MASK access,
                                     ULONG heap_size )
 {
+    WCHAR buffer[MAX_PATH];
     HANDLE ret;
 
-    if ((device && device->Length) || devmode)
+    if ((device && device->Length) || (devmode && !(flags & DF_WINE_CREATE_DESKTOP)))
     {
         RtlSetLastWin32Error( ERROR_INVALID_PARAMETER );
         return 0;
@@ -163,6 +164,15 @@ HDESK WINAPI NtUserCreateDesktopEx( OBJECT_ATTRIBUTES *attr, UNICODE_STRING *dev
         ret = wine_server_ptr_handle( reply->handle );
     }
     SERVER_END_REQ;
+    if (!devmode) return ret;
+
+    lstrcpynW( buffer, attr->ObjectName->Buffer, attr->ObjectName->Length / sizeof(WCHAR) + 1 );
+    if (!user_driver->pCreateDesktop( buffer, devmode->dmPelsWidth, devmode->dmPelsHeight ))
+    {
+        NtUserCloseDesktop( ret );
+        return 0;
+    }
+
     return ret;
 }
 

include/ntuser.h

@@ -286,6 +286,9 @@ struct unpack_dde_message_params
 #define SPY_RESULT_OK      0x0001
 #define SPY_RESULT_DEFWND  0x0002
 
+/* CreateDesktop wine specific flag */
+#define DF_WINE_CREATE_DESKTOP   0x80000000
+
 /* NtUserMessageCall codes */
 enum
 {

include/wine/gdi_driver.h

@@ -307,6 +307,7 @@ struct user_driver_funcs
     INT     (*pGetDisplayDepth)(LPCWSTR,BOOL);
     BOOL    (*pUpdateDisplayDevices)(const struct gdi_device_manager *,BOOL,void*);
     /* windowing functions */
+    BOOL    (*pCreateDesktop)(const WCHAR *,UINT,UINT);
     BOOL    (*pCreateWindow)(HWND);
     LRESULT (*pDesktopWindowProc)(HWND,UINT,WPARAM,LPARAM);
     void    (*pDestroyWindow)(HWND);

programs/explorer/desktop.c

@@ -1089,9 +1089,11 @@ void manage_desktop( WCHAR *arg )
 
     if (name && width && height)
     {
+        DEVMODEW devmode = {.dmPelsWidth = width, .dmPelsHeight = height};
         /* magic: desktop "root" means use the root window */
-        using_root = !wcsicmp( name, L"root" );
-        if (!(desktop = CreateDesktopW( name, NULL, NULL, 0, DESKTOP_ALL_ACCESS, NULL )))
+        if ((using_root = !wcsicmp( name, L"root" ))) desktop = CreateDesktopW( name, NULL, NULL, 0, DESKTOP_ALL_ACCESS, NULL );
+        else desktop = CreateDesktopW( name, NULL, &devmode, DF_WINE_CREATE_DESKTOP, DESKTOP_ALL_ACCESS, NULL );
+        if (!desktop)
         {
             WINE_ERR( "failed to create desktop %s error %ld\n", wine_dbgstr_w(name), GetLastError() );
             ExitProcess( 1 );