From 11fa53fb6627d5c1dce3fd07e464308c429367ac Mon Sep 17 00:00:00 2001
From: Henry Weller <http://openfoam.org>
Date: Fri, 8 Feb 2019 15:16:20 +0000
Subject: [PATCH] blockMeshMerge: Minor update for consistency with the "fast"
 algorithm

---
 etc/controlDict                               |  1 +
 src/mesh/blockMesh/blockMesh/blockMeshMerge.C | 28 +++++++------------
 2 files changed, 11 insertions(+), 18 deletions(-)

diff --git a/etc/controlDict b/etc/controlDict
index b056a79b4b..bdd473deb3 100644
--- a/etc/controlDict
+++ b/etc/controlDict
@@ -345,6 +345,7 @@ DebugSwitches
     blended             0;
     blobsSheetAtomization   0;
     blobsSwirlInjector  0;
+    blockMesh           0;
     booleanSurface      0;
     boundaryCutter      0;
     boundaryMesh        0;
diff --git a/src/mesh/blockMesh/blockMesh/blockMeshMerge.C b/src/mesh/blockMesh/blockMesh/blockMeshMerge.C
index 77da869940..7a081a6068 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     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2019 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -56,9 +56,7 @@ void Foam::blockMesh::calcMergeInfo()
     }
 
     // set unused to -1
-    mergeList_.setSize(nPoints_);
-    mergeList_ = -1;
-
+    mergeList_.setSize(nPoints_, -1);
 
     const pointField& blockPoints = topology().points();
     const cellList& blockCells = topology().cells();
@@ -548,35 +546,29 @@ void Foam::blockMesh::calcMergeInfo()
     }
 
 
-    // Sort merge list to return new point label (in new shorter list)
-    // given old point label
-    label newPointLabel = 0;
+    // Sort merge list and count number of unique points
+    label nUniqPoints = 0;
 
-    forAll(mergeList_, pointLabel)
+    forAll(mergeList_, pointi)
     {
-        if (mergeList_[pointLabel] > pointLabel)
+        if (mergeList_[pointi] > pointi)
         {
             FatalErrorInFunction
                 << "Merge list contains point index out of range"
                 << exit(FatalError);
         }
 
-        if
-        (
-            mergeList_[pointLabel] == -1
-         || mergeList_[pointLabel] == pointLabel
-        )
+        if (mergeList_[pointi] == -1 || mergeList_[pointi] == pointi)
         {
-            mergeList_[pointLabel] = newPointLabel;
-            newPointLabel++;
+            mergeList_[pointi] = nUniqPoints++;
         }
         else
         {
-            mergeList_[pointLabel] = mergeList_[mergeList_[pointLabel]];
+            mergeList_[pointi] = mergeList_[mergeList_[pointi]];
         }
     }
 
-    nPoints_ = newPointLabel;
+    nPoints_ = nUniqPoints;
 }