Index: win32ss/gdi/ntgdi/bitblt.c
===================================================================
--- win32ss/gdi/ntgdi/bitblt.c	(revision 75615)
+++ win32ss/gdi/ntgdi/bitblt.c	(working copy)
@@ -382,7 +382,7 @@
     ahDC[1] = UsesSource ? hdcSrc : NULL;
     if (!GDIOBJ_bLockMultipleObjects(2, (HGDIOBJ*)ahDC, apObj, GDIObjType_DC_TYPE))
     {
-        WARN("Invalid dc handle (dest=0x%p, src=0x%p) passed to NtGdiAlphaBlend\n", hdcDest, hdcSrc);
+        WARN("Invalid dc handle (dest=0x%p, src=0x%p) passed to NtGdiMaskBlt\n", hdcDest, hdcSrc);
         EngSetLastError(ERROR_INVALID_HANDLE);
         return FALSE;
     }
@@ -393,7 +393,7 @@
     if (NULL == DCDest)
     {
         if(DCSrc) DC_UnlockDc(DCSrc);
-        WARN("Invalid destination dc handle (0x%p) passed to NtGdiBitBlt\n", hdcDest);
+        WARN("Invalid destination dc handle (0x%p) passed to NtGdiMaskBlt\n", hdcDest);
         return FALSE;
     }
 
@@ -1496,7 +1496,9 @@
     /* Check if the pixel is outside the surface */
     psurfSrc = pdc->dclevel.pSurface;
     if ((ptlSrc.x >= psurfSrc->SurfObj.sizlBitmap.cx) ||
-        (ptlSrc.y >= psurfSrc->SurfObj.sizlBitmap.cy))
+        (ptlSrc.y >= psurfSrc->SurfObj.sizlBitmap.cy) ||
+        (ptlSrc.x < 0) ||
+        (ptlSrc.y < 0))
     {
         /* Fail! */
         goto leave;