crashtesting: isNaN as fUnitCircleWidthAngleDegree

presumably since recent tdf#50934 work

affect files are:

forums/xlsx/forum-mso-en4-295952.xlsx
forums/xlsx/forum-mso-en4-523214.xlsx
forums/xlsx/forum-mso-en4-656086.xlsx
forums/xlsx/forum-mso-en4-702681.xlsx

Change-Id: Ifc436d382f9cda13d2ae4459d436a72c5e40d8aa
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/163784
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>
diff --git a/chart2/source/view/main/ShapeFactory.cxx b/chart2/source/view/main/ShapeFactory.cxx
index 228d4b2..0e572a7 100644
--- a/chart2/source/view/main/ShapeFactory.cxx
+++ b/chart2/source/view/main/ShapeFactory.cxx
@@ -898,6 +898,12 @@ rtl::Reference<SvxShapePolyPolygon>
    xShape->setShapeKind(SdrObjKind::PathFill); // aka ClosedBezierShape
    xTarget->addShape(*xShape); //need to add the shape before setting of properties

    if (std::isnan(fUnitCircleWidthAngleDegree))
    {
        SAL_WARN("chart2", "fUnitCircleWidthAngleDegree isNaN");
        return xShape;
    }

    //set properties
    try
    {