gdi32: Return correct color depth for display DCs in GetDeviceCaps().

dlls/gdi32/driver.c

@@ -460,7 +460,24 @@ static INT CDECL nulldrv_GetDeviceCaps( PHYSDEV dev, INT cap )
 
         return pGetSystemMetrics ? pGetSystemMetrics( SM_CYSCREEN ) : 480;
     }
-    case BITSPIXEL:       return 32;
+    case BITSPIXEL:
+    {
+        DEVMODEW devmode;
+        WCHAR *display;
+        DC *dc;
+
+        if (GetDeviceCaps( dev->hdc, TECHNOLOGY ) == DT_RASDISPLAY && pEnumDisplaySettingsW)
+        {
+            dc = get_nulldrv_dc( dev );
+            display = dc->display[0] ? dc->display : NULL;
+            memset( &devmode, 0, sizeof(devmode) );
+            devmode.dmSize = sizeof(devmode);
+            if (pEnumDisplaySettingsW( display, ENUM_CURRENT_SETTINGS, &devmode )
+                && devmode.dmFields & DM_BITSPERPEL && devmode.dmBitsPerPel)
+                return devmode.dmBitsPerPel;
+        }
+        return 32;
+    }
     case PLANES:          return 1;
     case NUMBRUSHES:      return -1;
     case NUMPENS:         return -1;

dlls/user32/tests/monitor.c

@@ -2068,7 +2068,6 @@ static void _check_display_dc(INT line, HDC hdc, const DEVMODEA *dm, BOOL allow_
             dm->dmDisplayFrequency, value);
 
     value = GetDeviceCaps(hdc, BITSPIXEL);
-    todo_wine_if(dm->dmBitsPerPel != 32)
     ok_(__FILE__, line)(value == dm->dmBitsPerPel, "Expected BITSPIXEL %d, got %d.\n",
             dm->dmBitsPerPel, value);
 

dlls/winex11.drv/init.c

@@ -162,8 +162,6 @@ static INT CDECL X11DRV_GetDeviceCaps( PHYSDEV dev, INT cap )
 {
     switch(cap)
     {
-    case BITSPIXEL:
-        return screen_bpp;
     case SIZEPALETTE:
         return palette_size;
     default: