From 02c7257eb01372d16aae12d9190912220e335c47 Mon Sep 17 00:00:00 2001
From: Henry Weller <http://cfd.direct>
Date: Mon, 5 Dec 2022 19:54:39 +0000
Subject: [PATCH] ZoltanDecomp: Check for no points on any processor during
 redistribution and throw a fatal error

Zoltan hangs if a processor has no points/cells during redistribution and
unfortunatel Zoltan can generate distributions in which one or processors has no
cells.
---
 src/parallel/decompose/zoltanDecomp/zoltanDecomp.C | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/parallel/decompose/zoltanDecomp/zoltanDecomp.C b/src/parallel/decompose/zoltanDecomp/zoltanDecomp.C
index fee4e61ce8..d5979c3ed2 100644
--- a/src/parallel/decompose/zoltanDecomp/zoltanDecomp.C
+++ b/src/parallel/decompose/zoltanDecomp/zoltanDecomp.C
@@ -248,6 +248,14 @@ Foam::label Foam::zoltanDecomp::decompose
     List<label>& finalDecomp
 ) const
 {
+    if (Pstream::parRun() && !points.size())
+    {
+        Pout<< "No points on processor " << Pstream::myProcNo() << nl
+            << "    Zoltan cannot redistribute without points"
+               "on all processors." << endl;
+        FatalErrorInFunction << exit(FatalError);
+    }
+
     stringList args(1);
     args[0] = "zoltanDecomp";