0027033: Modeling -- ensure stable result of area calculation

The method BRepGProp_Face::LKnots has been corrected to make proper initialization of the output data for the case of a circle.
Added test case bugs/modalg_6/bug27033

Author: msv

src/BRepGProp/BRepGProp_Face.cxx

@@ -470,7 +470,7 @@ void BRepGProp_Face::LKnots(TColStd_Array1OfReal& Knots) const
     break;
   case GeomAbs_Circle:
   case GeomAbs_Ellipse:
-    Knots(1) = 0.0;  Knots(2) = M_PI*2.0/3.0;  Knots(3) = M_PI*4.0/3.0;  Knots(2) = M_PI*6.0/3.0;
+    Knots(1) = 0.0;  Knots(2) = M_PI*2.0/3.0;  Knots(3) = M_PI*4.0/3.0;  Knots(4) = M_PI*6.0/3.0;
     break;
   case GeomAbs_Parabola:
   case GeomAbs_Hyperbola:

tests/bugs/modalg_6/bug27033

@@ -0,0 +1,16 @@
+puts "========="
+puts "OCC27033"
+puts "========="
+puts ""
+#############################################################
+# Modeling -- ensure stable result of area calculation
+#############################################################
+
+pload XDE
+stepread [locate_data_file OCC11856.stp] a *
+
+for {set i 1} {$i < 100} {incr i} {
+  checkprops a_1 -s 647779 -eps 0.1
+}
+
+checkview -display a_1 -2d -path ${imagedir}/${test_image}.png