[AD] Simple fix for the WinXP black screen bug

[Eric Botcazou <ebotcazou@xxxxxxxxxx>]

Javier privately suggested a new fix for the WinXP black screen bug, simpler 
than the one he originally devised back in October. It allows me to get rid 
of the cruft I added to the overlay windowed driver in order to accomodate 
to the former fix.

Applied to trunk and branch.

-- 
Eric Botcazou

Index: src/win/wddovl.c
===================================================================
RCS file: /cvsroot/alleg/allegro/src/win/wddovl.c,v
retrieving revision 1.42
diff -u -r1.42 wddovl.c
--- src/win/wddovl.c	15 Oct 2002 18:10:42 -0000	1.42
+++ src/win/wddovl.c	19 May 2003 11:17:35 -0000
@@ -85,8 +85,8 @@
 
 static char gfx_driver_desc[256] = EMPTY_STRING;
 static DDRAW_SURFACE *overlay_surface = NULL;
-static BITMAP *viewport = NULL, *background = NULL;
 static BOOL overlay_visible = FALSE;
+static HBRUSH overlay_brush;
 
 
 
@@ -110,11 +110,6 @@
    HRESULT hr;
    RECT dest_rect = {x, y, x + w, y + h};
 
-   /* paint the window background with the overlay color key */
-   background->x_ofs = x + viewport->x_ofs;
-   background->y_ofs = y + viewport->y_ofs;
-   clear_to_color(background, background->vtable->mask_color);
-
    /* show the overlay surface */
    hr = IDirectDrawSurface2_UpdateOverlay(overlay_surface->id, NULL,
                                           primary_surface->id, &dest_rect,
@@ -310,6 +305,10 @@
    if (finalize_directx_init() != 0)
       goto Error;
 
+   /* Paint window background with overlay color key. */
+   overlay_brush = CreateSolidBrush(MASK_COLOR_32);
+   SetClassLong(allegro_wnd, GCL_HBRBACKGROUND, (LONG) overlay_brush);
+
    if (adjust_window(w, h) != 0) {
       _TRACE("window size not supported.\n");
       ustrzcpy(allegro_error, ALLEGRO_ERROR_SIZE, get_config_text("Resolution not supported"));
@@ -366,8 +365,6 @@
       goto Error;
 
    forefront_bitmap = make_bitmap_from_surface(overlay_surface, w, h, BMP_ID_VIDEO);
-   viewport = make_bitmap_from_surface(primary_surface, w, h, BMP_ID_VIDEO);
-   background = create_sub_bitmap(viewport, 0, 0, w, h);
 
    /* set the overlay color key */
    key.dwColorSpaceLowValue = forefront_bitmap->vtable->mask_color;
@@ -430,16 +427,11 @@
    /* destroy the overlay surface */
    if (overlay_surface) {
       hide_overlay();
+      SetClassLong(allegro_wnd, GCL_HBRBACKGROUND, (LONG) NULL);
+      DeleteObject(overlay_brush);
       gfx_directx_destroy_surface(overlay_surface);
       overlay_surface = NULL;
       forefront_bitmap = NULL;
-   }
-
-   /* destroy the viewport */
-   if (viewport) {
-      destroy_bitmap(background);
-      free(viewport);
-      viewport = NULL;
    }
 
    gfx_directx_exit(NULL);
Index: src/win/wwnd.c
===================================================================
RCS file: /cvsroot/alleg/allegro/src/win/wwnd.c,v
retrieving revision 1.74
diff -u -r1.74 wwnd.c
--- src/win/wwnd.c	14 Jan 2003 16:51:09 -0000	1.74
+++ src/win/wwnd.c	19 May 2003 11:17:36 -0000
@@ -282,14 +282,6 @@
          wnd_height = HIWORD(lparam);
          break;
 
-      case WM_ERASEBKGND:
-         /* Disable the default background eraser in order
-          * to prevent conflicts on NT kernels.
-          */
-         if (!user_wnd_proc || win_gfx_driver)
-            return 1;
-         break;
-
       case WM_PAINT:
          if (!user_wnd_proc || win_gfx_driver) {
             BeginPaint(wnd, &ps);
@@ -368,7 +360,7 @@
       if (!wnd_class.hIcon)
          wnd_class.hIcon = LoadIcon(NULL, IDI_APPLICATION);
       wnd_class.hCursor = LoadCursor(NULL, IDC_ARROW);
-      wnd_class.hbrBackground = GetStockObject(BLACK_BRUSH);
+      wnd_class.hbrBackground = NULL;
       wnd_class.lpszMenuName = NULL;
       wnd_class.lpszClassName = ALLEGRO_WND_CLASS;