From 78338e590ed0cc786ad74ef59198c1228fdd154c Mon Sep 17 00:00:00 2001
From: Will Bainbridge <http://cfd.direct>
Date: Wed, 29 Nov 2017 11:31:16 +0000
Subject: [PATCH] polyMesh: Stopped re-seeding of RNG on each cell-tree update

This is a quick fix. What actually needs doing is the Random and
cachedRandom classes need rewriting in terms of the random number
functionality in the C++11 STL. These can be initialised/seeded
per-object, which makes this sort of bug go away.

This resolves bug report https://bugs.openfoam.org/view.php?id=2772
---
 src/OpenFOAM/meshes/polyMesh/polyMesh.C | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/OpenFOAM/meshes/polyMesh/polyMesh.C b/src/OpenFOAM/meshes/polyMesh/polyMesh.C
index 23943df92..9e46e8e0c 100644
--- a/src/OpenFOAM/meshes/polyMesh/polyMesh.C
+++ b/src/OpenFOAM/meshes/polyMesh/polyMesh.C
@@ -878,7 +878,7 @@ Foam::polyMesh::cellTree() const
     {
         treeBoundBox overallBb(points());
 
-        Random rndGen(261782);
+        static Random rndGen(261782);
 
         overallBb = overallBb.extend(rndGen, 1e-4);
         overallBb.min() -= point(ROOTVSMALL, ROOTVSMALL, ROOTVSMALL);