From c96ff47d98590a546d39baea8bb98ee587416626 Mon Sep 17 00:00:00 2001
From: Henry Weller <http://openfoam.org>
Date: Mon, 9 Oct 2017 21:33:02 +0100
Subject: [PATCH] ENH: blockMesh: Added switch to disable face correspondence
 checking

To disable face correspondence checking set

    checkFaceCorrespondence off;

in blockMeshDict.  This is necessary in the rare cases where adjacent block
faces do not need to correspond because they are geometrically collapsed,
e.g. to form a pole/axis.

Resolves bug-report https://bugs.openfoam.org/view.php?id=2711
---
 src/mesh/blockMesh/blockMesh/blockMesh.C      | 6 +++++-
 src/mesh/blockMesh/blockMesh/blockMesh.H      | 5 ++++-
 src/mesh/blockMesh/blockMesh/blockMeshMerge.C | 8 ++++++--
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/mesh/blockMesh/blockMesh/blockMesh.C b/src/mesh/blockMesh/blockMesh/blockMesh.C
index a4d6d8c38e..de3130d9d8 100644
--- a/src/mesh/blockMesh/blockMesh/blockMesh.C
+++ b/src/mesh/blockMesh/blockMesh/blockMesh.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2017 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -40,6 +40,10 @@ Foam::blockMesh::blockMesh(const IOdictionary& dict, const word& regionName)
 :
     meshDict_(dict),
     verboseOutput(meshDict_.lookupOrDefault("verbose", true)),
+    checkFaceCorrespondence_
+    (
+        meshDict_.lookupOrDefault("checkFaceCorrespondence", true)
+    ),
     geometry_
     (
         IOobject
diff --git a/src/mesh/blockMesh/blockMesh/blockMesh.H b/src/mesh/blockMesh/blockMesh/blockMesh.H
index 74471c8e90..9510553275 100644
--- a/src/mesh/blockMesh/blockMesh/blockMesh.H
+++ b/src/mesh/blockMesh/blockMesh/blockMesh.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2017 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -71,6 +71,9 @@ class blockMesh
         //- Switch for verbose output
         bool verboseOutput;
 
+        //- Switch checking face consistency (defaults to true)
+        bool checkFaceCorrespondence_;
+
         //- Optional searchable geometry to project face-points to
         searchableSurfaces geometry_;
 
diff --git a/src/mesh/blockMesh/blockMesh/blockMeshMerge.C b/src/mesh/blockMesh/blockMesh/blockMeshMerge.C
index 1cccc5a2fe..2ef5796037 100644
--- a/src/mesh/blockMesh/blockMesh/blockMeshMerge.C
+++ b/src/mesh/blockMesh/blockMesh/blockMeshMerge.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2017 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -212,7 +212,11 @@ void Foam::blockMesh::calcMergeInfo()
         const List<FixedList<label, 4>>& blockNfaceFaces =
             blocks[blockNlabel].boundaryPatches()[blockNfaceLabel];
 
-        if (blockPfaceFaces.size() != blockNfaceFaces.size())
+        if
+        (
+            checkFaceCorrespondence_
+         && blockPfaceFaces.size() != blockNfaceFaces.size()
+        )
         {
             FatalErrorInFunction
                 << "Inconsistent number of faces between block pair "