Fix BSOD when executing gdi32_winetest bitmap

svn path=/trunk/; revision=21563

diff --git a/reactos/subsystems/win32/win32k/objects/dibobj.c b/reactos/subsystems/win32/win32k/objects/dibobj.c
index 77959e6..b870c61 100644 (file)
--- a/reactos/subsystems/win32/win32k/objects/dibobj.c
+++ b/reactos/subsystems/win32/win32k/objects/dibobj.c
@@ -454,6 +454,13 @@ NtGdiGetDIBits(HDC hDC,
             BitmapFormat(Info->bmiHeader.biBitCount, Info->bmiHeader.biCompression),
             0 < Info->bmiHeader.biHeight ? 0 : BMF_TOPDOWN,
             Bits);
+         
+         if(DestBitmap == NULL)
+         {
+            BITMAPOBJ_UnlockBitmap(BitmapObj);
+            return 0;
+         }
+         
          DestSurfObj = EngLockSurface((HSURF)DestBitmap);
 
          SourcePalette = PALETTE_LockPalette(hSourcePalette);