From da98104a79891629ffadd6aba1147f7e5f783f03 Mon Sep 17 00:00:00 2001
From: Kutalmis Bercin <kutalmis.bercin@esi-group.com>
Date: Wed, 21 Jun 2023 13:00:09 +0100
Subject: [PATCH] COMP: streamFunction: avoid over-eager optimisation (fixes
 #2603)

---
 src/functionObjects/field/streamFunction/streamFunction.C | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/functionObjects/field/streamFunction/streamFunction.C b/src/functionObjects/field/streamFunction/streamFunction.C
index 3329d20131..741efa28d4 100644
--- a/src/functionObjects/field/streamFunction/streamFunction.C
+++ b/src/functionObjects/field/streamFunction/streamFunction.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016 OpenFOAM Foundation
-    Copyright (C) 2019-2020 OpenCFD Ltd.
+    Copyright (C) 2019-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -64,8 +64,6 @@ Foam::tmp<Foam::pointScalarField> Foam::functionObjects::streamFunction::calc
       & Vector<label>(Vector<label>::X, Vector<label>::Y, Vector<label>::Z)
     );
 
-    scalar thickness = vector(slabNormal) & mesh_.bounds().span();
-
     const pointMesh& pMesh = pointMesh::New(mesh_);
 
     auto tstreamFunction = tmp<pointScalarField>::New
@@ -395,6 +393,9 @@ Foam::tmp<Foam::pointScalarField> Foam::functionObjects::streamFunction::calc
     } while (!finished);
 
     // Normalise the stream-function by the 2D mesh thickness
+    // calculate thickness here to avoid compiler oddness (#2603)
+    const scalar thickness = vector(slabNormal) & mesh_.bounds().span();
+
     streamFunction /= thickness;
     streamFunction.boundaryFieldRef() = 0.0;