From ab551573587cd5e685bed5f554f78cc3511f5cbe Mon Sep 17 00:00:00 2001
From: mattijs <mattijs>
Date: Thu, 10 Sep 2020 13:38:59 +0100
Subject: [PATCH] BUG: snappyHexMesh: fixes #1836.

When truncating layers in one go (nBufferCellsNoExtrude -1) it
should set the nCells per face to be the min of the number of points
per edge.
---
 .../snappyHexMeshDriver/snappyLayerDriver.C     | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyLayerDriver.C b/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyLayerDriver.C
index 5c5a91e448..09b64e7861 100644
--- a/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyLayerDriver.C
+++ b/src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyLayerDriver.C
@@ -2407,10 +2407,21 @@ void Foam::snappyLayerDriver::setupLayerInfoTruncation
 
             forAll(f, fp)
             {
-                if (patchNLayers[f[fp]] > 0)
+                const label nPointLayers = patchNLayers[f[fp]];
+                if (nPointLayers > 0)
                 {
-                    nPatchFaceLayers[patchFacei] = patchNLayers[f[fp]];
-                    break;
+                    if (nPatchFaceLayers[patchFacei] == -1)
+                    {
+                        nPatchFaceLayers[patchFacei] = nPointLayers;
+                    }
+                    else
+                    {
+                        nPatchFaceLayers[patchFacei] = min
+                        (
+                            nPatchFaceLayers[patchFacei],
+                            nPointLayers
+                        );
+                    }
                 }
             }
         }