ENH: ptscotchDecomp : allow zero sized domains

src/parallel/decompose/ptscotchDecomp/ptscotchDecompTemplates.C

+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2010-2010 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "ptscotchDecomp.H"
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+// Insert at front of list
+template<class Type>
+void Foam::ptscotchDecomp::prepend
+(
+    const UList<Type>& extraLst,
+    List<Type>& lst
+)
+{
+    label nExtra = extraLst.size();
+
+    // Make space for initial elements
+    lst.setSize(lst.size() + nExtra);
+    for (label i = lst.size()-1; i >= nExtra; i--)
+    {
+        lst[i] = lst[i-nExtra];
+    }
+
+    // Insert at front
+    forAll(extraLst, i)
+    {
+        lst[i] = extraLst[i];
+    }
+}
+
+
+// Insert at back of list
+template<class Type>
+void Foam::ptscotchDecomp::append
+(
+    const UList<Type>& extraLst,
+    List<Type>& lst
+)
+{
+    label sz = lst.size();
+
+    // Make space for initial elements
+    lst.setSize(sz + extraLst.size());
+
+    // Insert at back
+    forAll(extraLst, i)
+    {
+        lst[sz++] = extraLst[i];
+    }
+}
+
+
+// ************************************************************************* //