BUG: Fixing constructors from dictionary to avoid hanging in parallel when patch size is zero

src/finiteVolume/fields/fvPatchFields/derived/swirlFanVelocity/swirlFanVelocityFvPatchField.C

@@ -145,7 +145,7 @@ Foam::swirlFanVelocityFvPatchField::swirlFanVelocityFvPatchField
         dict.lookupOrDefault
         (
             "origin",
-            patch().size()
+            returnReduce(patch().size(), maxOp<label>())
           ? gSum(patch().Cf()*patch().magSf())/gSum(patch().magSf())
           : Zero
         )

src/finiteVolume/fields/fvPatchFields/derived/swirlFlowRateInletVelocity/swirlFlowRateInletVelocityFvPatchVectorField.C

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2017 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2018 OpenCFD
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -65,7 +65,7 @@ swirlFlowRateInletVelocityFvPatchVectorField
         dict.lookupOrDefault
         (
             "origin",
-            patch().size()
+            returnReduce(patch().size(), maxOp<label>())
           ? gSum(patch().Cf()*patch().magSf())/gSum(patch().magSf())
           : Zero
         )