Mantid solid angle bug change cylinder axis patch.

sabug_cylaxis.diff

diff --git a/Framework/Geometry/src/Objects/CSGObject.cpp b/Framework/Geometry/src/Objects/CSGObject.cpp
index 286d1d953f8..eda0fa258d5 100644
--- a/Framework/Geometry/src/Objects/CSGObject.cpp
+++ b/Framework/Geometry/src/Objects/CSGObject.cpp
@@ -307,8 +307,9 @@ double cylinderSolidAngle(const V3D &observer, const V3D &centre, const V3D &axi
   // axis points up the +Z axis and then rotated into their final position

   // Required rotation
-  constexpr V3D initial_axis(0., 0., 1.0);
-  const Quat transform(initial_axis, axis);
+  constexpr V3D initial_axis(0., 1., 0.);
+  const V3D axis_direction = normalize(axis);
+  const Quat transform(initial_axis, axis_direction);

   // Do the base cap which is a point at the centre and nslices points around it
   constexpr double angle_step = 2 * M_PI / static_cast<double>(Cylinder::g_NSLICES);
@@ -323,13 +324,13 @@ double cylinderSolidAngle(const V3D &observer, const V3D &centre, const V3D &axi
     for (int sl = 0; sl < Cylinder::g_NSLICES; ++sl) {
       double x = radius * std::cos(angle_step * sl);
       double y = radius * std::sin(angle_step * sl);
-      V3D pt1 = V3D(x, y, z0);
-      V3D pt2 = V3D(x, y, z1);
+      V3D pt1 = V3D(x, z0, -y);
+      V3D pt2 = V3D(x, z1, -y);
       int vertex = (sl + 1) % Cylinder::g_NSLICES;
       x = radius * std::cos(angle_step * vertex);
       y = radius * std::sin(angle_step * vertex);
-      V3D pt3 = V3D(x, y, z0);
-      V3D pt4 = V3D(x, y, z1);
+      V3D pt3 = V3D(x, z0, -y);
+      V3D pt4 = V3D(x, z1, -y);
       // Rotations
       transform.rotate(pt1);
       transform.rotate(pt3);