DPtoLP needs to round the result.

include/gdi.h

@@ -402,24 +402,24 @@ static inline void WINE_UNUSED INTERNAL_LPTODP(DC *dc, LPPOINT point)
 }
 
 #define XDPTOLP(dc,x) \
-    (((x)-(dc)->vportOrgX) * (dc)->wndExtX / (dc)->vportExtX+(dc)->wndOrgX)
+    (MulDiv(((x)-(dc)->vportOrgX), (dc)->wndExtX, (dc)->vportExtX) + (dc)->wndOrgX)
 #define YDPTOLP(dc,y) \
-    (((y)-(dc)->vportOrgY) * (dc)->wndExtY / (dc)->vportExtY+(dc)->wndOrgY)
+    (MulDiv(((y)-(dc)->vportOrgY), (dc)->wndExtY, (dc)->vportExtY) + (dc)->wndOrgY)
 #define XLPTODP(dc,x) \
-    (((x)-(dc)->wndOrgX) * (dc)->vportExtX / (dc)->wndExtX+(dc)->vportOrgX)
+    (MulDiv(((x)-(dc)->wndOrgX), (dc)->vportExtX, (dc)->wndExtX) + (dc)->vportOrgX)
 #define YLPTODP(dc,y) \
-    (((y)-(dc)->wndOrgY) * (dc)->vportExtY / (dc)->wndExtY+(dc)->vportOrgY)
+    (MulDiv(((y)-(dc)->wndOrgY), (dc)->vportExtY, (dc)->wndExtY) + (dc)->vportOrgY)
 
   /* Device <-> logical size conversion */
 
 #define XDSTOLS(dc,x) \
-    ((x) * (dc)->wndExtX / (dc)->vportExtX)
+    MulDiv((x), (dc)->wndExtX, (dc)->vportExtX)
 #define YDSTOLS(dc,y) \
-    ((y) * (dc)->wndExtY / (dc)->vportExtY)
+    MulDiv((y), (dc)->wndExtY, (dc)->vportExtY)
 #define XLSTODS(dc,x) \
-    ((x) * (dc)->vportExtX / (dc)->wndExtX)
+    MulDiv((x), (dc)->vportExtX, (dc)->wndExtX)
 #define YLSTODS(dc,y) \
-    ((y) * (dc)->vportExtY / (dc)->wndExtY)
+    MulDiv((y), (dc)->vportExtY, (dc)->wndExtY)
 
   /* GDI local heap */
 

objects/gdiobj.c

@@ -1029,13 +1029,42 @@ INT WINAPI MulDiv(
 ) {
 #if (SIZEOF_LONG_LONG >= 8)
     long long ret;
+
     if (!nDivisor) return -1;
-    ret = (((long long)nMultiplicand * nMultiplier) + (nDivisor/2)) / nDivisor;
+
+    /* We want to deal with a positive divisor to simplify the logic. */
+    if (nDivisor < 0)
+    {
+      nMultiplicand = - nMultiplicand;
+      nDivisor = -nDivisor;
+    }
+
+    /* If the result is positive, we "add" to round. else, we subtract to round. */
+    if ( ( (nMultiplicand <  0) && (nMultiplier <  0) ) ||
+	 ( (nMultiplicand >= 0) && (nMultiplier >= 0) ) )
+      ret = (((long long)nMultiplicand * nMultiplier) + (nDivisor/2)) / nDivisor;
+    else
+      ret = (((long long)nMultiplicand * nMultiplier) - (nDivisor/2)) / nDivisor;
+
     if ((ret > 2147483647) || (ret < -2147483647)) return -1;
     return ret;
 #else
     if (!nDivisor) return -1;
-    return ((nMultiplicand * nMultiplier) + (nDivisor/2)) / nDivisor;
+
+    /* We want to deal with a positive divisor to simplify the logic. */
+    if (nDivisor < 0)
+    {
+      nMultiplicand = - nMultiplicand;
+      nDivisor = -nDivisor;
+    }
+
+    /* If the result is positive, we "add" to round. else, we subtract to round. */
+    if ( ( (nMultiplicand <  0) && (nMultiplier <  0) ) ||
+	 ( (nMultiplicand >= 0) && (nMultiplier >= 0) ) )
+      return ((nMultiplicand * nMultiplier) + (nDivisor/2)) / nDivisor;
+ 
+    return ((nMultiplicand * nMultiplier) - (nDivisor/2)) / nDivisor;
+    
 #endif
 }
 /*******************************************************************