From 73a3fbe44685cc421967541bef5cdb25f157d6b7 Mon Sep 17 00:00:00 2001
From: Will Bainbridge <http://cfd.direct>
Date: Thu, 21 Dec 2023 19:26:08 +0000
Subject: [PATCH] patchToPatches::intersection: Fix error part calculation for
 reversed targets

---
 .../intersection/intersectionPatchToPatch.C         | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/src/meshTools/patchToPatch/intersection/intersectionPatchToPatch.C b/src/meshTools/patchToPatch/intersection/intersectionPatchToPatch.C
index eddb99f45b..1cc13ccc74 100644
--- a/src/meshTools/patchToPatch/intersection/intersectionPatchToPatch.C
+++ b/src/meshTools/patchToPatch/intersection/intersectionPatchToPatch.C
@@ -394,14 +394,8 @@ bool Foam::patchToPatches::intersection::intersectFaces
 
                     if (tgtFaceEdgei < tgtPatch[tgtFacei].size())
                     {
-                        if (reverse())
-                        {
-                            tgtFaceEdgePart_[tgtFaceEdgei] += ictEdgePart;
-                        }
-                        else
-                        {
-                            tgtFaceEdgePart_[tgtFaceEdgei] -= ictEdgePart;
-                        }
+                        tgtFaceEdgePart_[tgtFaceEdgei] +=
+                            reverse() ? ictEdgePart : -ictEdgePart;
                         ictEdgeSide = -1;
                     }
                     else
@@ -456,7 +450,8 @@ bool Foam::patchToPatches::intersection::intersectFaces
             srcFaceEdgeParts_[srcFacei][srcFaceEdgei] +=
                 srcFaceEdgePart_[srcFaceEdgei];
         }
-        srcErrorParts_[srcFacei] -= sum(tgtFaceEdgePart_);
+        srcErrorParts_[srcFacei] +=
+            reverse() ? sum(tgtFaceEdgePart_) : -sum(tgtFaceEdgePart_);
         srcErrorParts_[srcFacei] += errorPart;
     }