ofz: floating point exception in values close to zero

Change-Id: Idd8c7d4dd42c63f4f4a67ba61b9f3760ec04f2f1

vcl/source/gdi/svmconverter.cxx

@@ -171,7 +171,21 @@ bool ImplReadMapMode(SvStream& rIStm, MapMode& rMapMode)
         return false;
     }
 
-    rMapMode = MapMode( (MapUnit) nUnit, aOrg, Fraction( nXNum, nXDenom ), Fraction( nYNum, nYDenom ) );
+    Fraction aX(nXNum, nXDenom);
+    if (!aX.IsValid() || rtl::math::round(aX, 6) == 0.0)
+    {
+        SAL_WARN("vcl.gdi", "Parsing error: invalid mapmode fraction");
+        return false;
+    }
+
+    Fraction aY(nYNum, nYDenom);
+    if (!aY.IsValid() || rtl::math::round(aY, 6) == 0.0)
+    {
+        SAL_WARN("vcl.gdi", "Parsing error: invalid mapmode fraction");
+        return false;
+    }
+
+    rMapMode = MapMode((MapUnit) nUnit, aOrg, aX, aY);
 
     return true;
 }