gdi32/enhmfdrv: When blitting, don't crash if the source is NULL.

dlls/gdi32/enhmfdrv/bitblt.c

@@ -79,10 +79,14 @@ static BOOL EMFDRV_BitBlockTransfer(
     UINT bitsSize;
     UINT size;
     BITMAP  BM;
-    WORD nBPP;
+    WORD nBPP = 0;
     LPBITMAPINFOHEADER lpBmiH;
+    BOOL useSrc;
     EMFDRV_PDEVICE* physDevSrc = (EMFDRV_PDEVICE*)devSrc;
-    HBITMAP hBitmap = GetCurrentObject(physDevSrc->hdc, OBJ_BITMAP);
+    HBITMAP hBitmap = NULL;
+
+    useSrc = (((rop >> 2) & 0x330000) != (rop & 0x330000));
+    if (!physDevSrc && useSrc) return FALSE;
 
     if (emrType == EMR_BITBLT)
         emrSize = sizeof(EMRBITBLT);
@@ -91,15 +95,24 @@ static BOOL EMFDRV_BitBlockTransfer(
     else
         return FALSE;
 
+    if(useSrc)
+    {
+        hBitmap = GetCurrentObject(physDevSrc->hdc, OBJ_BITMAP);
+
         if(sizeof(BITMAP) != GetObjectW(hBitmap, sizeof(BITMAP), &BM))
             return FALSE;
 
         nBPP = BM.bmPlanes * BM.bmBitsPixel;
         if(nBPP > 8) nBPP = 24; /* FIXME Can't get 16bpp to work for some reason */
-
         bitsSize = DIB_GetDIBWidthBytes(BM.bmWidth, nBPP) * BM.bmHeight;
         bmiSize = sizeof(BITMAPINFOHEADER) +
             (nBPP <= 8 ? 1 << nBPP : 0) * sizeof(RGBQUAD);
+    }
+    else
+    {
+        bitsSize = bmiSize = 0;
+    }
+
    size = emrSize + bmiSize + bitsSize;
 
     pEMR = HeapAlloc(GetProcessHeap(), 0, size);
@@ -119,12 +132,28 @@ static BOOL EMFDRV_BitBlockTransfer(
     pEMR->dwRop = rop;
     pEMR->xSrc = xSrc;
     pEMR->ySrc = ySrc;
+    if (useSrc)
+    {
         GetWorldTransform(physDevSrc->hdc, &pEMR->xformSrc);
         pEMR->crBkColorSrc = GetBkColor(physDevSrc->hdc);
         pEMR->iUsageSrc = DIB_RGB_COLORS;
         pEMR->offBmiSrc = emrSize;
-    pEMR->cbBmiSrc = bmiSize;
         pEMR->offBitsSrc = emrSize + bmiSize;
+    }
+    else
+    {
+        pEMR->xformSrc.eM11 = 1.0;  /** FIXME:           */
+        pEMR->xformSrc.eM12 = 0.0;  /** Setting default  */
+        pEMR->xformSrc.eM21 = 0.0;  /** value.           */
+        pEMR->xformSrc.eM22 = 1.0;  /** Where should we  */
+        pEMR->xformSrc.eDx = 0.0;   /** get that info    */
+        pEMR->xformSrc.eDy = 0.0;   /** ????             */
+        pEMR->crBkColorSrc = 0;
+        pEMR->iUsageSrc = 0;
+        pEMR->offBmiSrc = 0;
+        pEMR->offBitsSrc = 0;
+    }
+    pEMR->cbBmiSrc = bmiSize;
     pEMR->cbBitsSrc = bitsSize;
     if (emrType == EMR_STRETCHBLT) 
     {
@@ -133,6 +162,8 @@ static BOOL EMFDRV_BitBlockTransfer(
         pEMRStretch->cySrc = heightSrc;
     }
 
+    if (useSrc)
+    {
         /* Initialize BITMAPINFO structure */
         lpBmiH = (LPBITMAPINFOHEADER)((BYTE*)pEMR + pEMR->offBmiSrc);
 
@@ -161,6 +192,12 @@ static BOOL EMFDRV_BitBlockTransfer(
         }
         else
             ret = FALSE;
+    }
+    else
+    {
+        ret = EMFDRV_WriteRecord(devDst, (EMR*)pEMR);
+        if (ret) EMFDRV_UpdateBBox(devDst, &(pEMR->rclBounds));
+    }
 
     HeapFree( GetProcessHeap(), 0, pEMR);
     return ret;