Visualization - AIS_Shape bounding box re-computation is not working properly #422

Fixed issue with bounding box cleaning algorithm that was causing the bounding box to be only increased.
Now the bounding box is increased and decreased to fit the shape.

src/AIS/AIS_Shape.cxx

@@ -735,6 +735,8 @@ const Bnd_Box& AIS_Shape::BoundingBox()
 
   if (myCompBB)
   {
+    // Clear the bounding box to re-compute it.
+    myBB.SetVoid();
     BRepBndLib::Add(myshape, myBB, false);
     myCompBB = Standard_False;
   }

tests/v3d/bugs/bug_gh421

@@ -0,0 +1,20 @@
+puts "============"
+puts "Visualization - Bounding box is not decreasing for mode 2 #421"
+puts "============"
+puts ""
+
+pload MODELING VISUALIZATION
+vclear
+
+box b 100 200 300
+vinit View1
+vdisplay b -dispMode 2
+# OK
+box b 10 200 300
+vdisplay b -dispMode 2
+
+vfit
+
+checkcolor 243 2 0 0 0
+
+vdump $::imagedir/${::casename}.png