From d95fc106b6837dea9ec9f2b0c2bc5c2b8892a6ab Mon Sep 17 00:00:00 2001
From: Henry Weller <http://cfd.direct>
Date: Wed, 21 Oct 2015 12:47:02 +0100
Subject: [PATCH] polyMesh: Ensure parallel consistency in findCell by ensuring
 tetBasePtIs is called on all processors, even for those with 0 cells.  Also
 use unique communicator for globalMeshData to avoid data transfer
 interference.

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1792
---
 .../polyMesh/globalMeshData/globalMeshData.C     |  9 ++++++++-
 src/OpenFOAM/meshes/polyMesh/polyMesh.C          | 16 ++++++++++------
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/OpenFOAM/meshes/polyMesh/globalMeshData/globalMeshData.C b/src/OpenFOAM/meshes/polyMesh/globalMeshData/globalMeshData.C
index b36a0e9579..5cf963fff3 100644
--- a/src/OpenFOAM/meshes/polyMesh/globalMeshData/globalMeshData.C
+++ b/src/OpenFOAM/meshes/polyMesh/globalMeshData/globalMeshData.C
@@ -2748,7 +2748,12 @@ void Foam::globalMeshData::updateMesh()
 
     // *** Temporary hack to avoid problems with overlapping communication
     // *** between these reductions and the calculation of deltaCoeffs
-    label comm = UPstream::worldComm + 1;
+    label comm = UPstream::allocateCommunicator
+    (
+        UPstream::worldComm,
+        identity(UPstream::nProcs()),
+        true
+    );
 
     // Total number of faces.
     nTotalFaces_ = returnReduce
@@ -2785,6 +2790,8 @@ void Foam::globalMeshData::updateMesh()
         comm
     );
 
+    UPstream::freeCommunicator(comm);
+
     if (debug)
     {
         Pout<< "globalMeshData : nTotalPoints_:" << nTotalPoints_ << endl;
diff --git a/src/OpenFOAM/meshes/polyMesh/polyMesh.C b/src/OpenFOAM/meshes/polyMesh/polyMesh.C
index 4b8012b71d..67ae5db9b3 100644
--- a/src/OpenFOAM/meshes/polyMesh/polyMesh.C
+++ b/src/OpenFOAM/meshes/polyMesh/polyMesh.C
@@ -1478,12 +1478,11 @@ Foam::label Foam::polyMesh::findCell
     const cellDecomposition decompMode
 ) const
 {
-    if (nCells() == 0)
-    {
-        return -1;
-    }
-
-    if (Pstream::parRun() && decompMode == FACE_DIAG_TRIS)
+    if
+    (
+        Pstream::parRun()
+     && (decompMode == FACE_DIAG_TRIS || decompMode == CELL_TETS)
+    )
     {
         // Force construction of face-diagonal decomposition before testing
         // for zero cells.
@@ -1494,6 +1493,11 @@ Foam::label Foam::polyMesh::findCell
         (void)tetBasePtIs();
     }
 
+    if (nCells() == 0)
+    {
+        return -1;
+    }
+
     if (decompMode == CELL_TETS)
     {
         // Advanced search method utilizing an octree