From ea497a076d56eee1462c60a1790a55637dd18c45 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20P=C3=B6schel?= <franz.poeschel@gmail.com>
Date: Thu, 12 Oct 2023 11:01:22 +0200
Subject: [PATCH] Bug fix: use mpi_rank_%i.toml when writing to TOML

---
 src/IO/JSON/JSONIOHandlerImpl.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/IO/JSON/JSONIOHandlerImpl.cpp b/src/IO/JSON/JSONIOHandlerImpl.cpp
index 68a1699a77..13f1d33d7e 100644
--- a/src/IO/JSON/JSONIOHandlerImpl.cpp
+++ b/src/IO/JSON/JSONIOHandlerImpl.cpp
@@ -1411,7 +1411,16 @@ auto JSONIOHandlerImpl::putJsonContents(
             // writeSingleFile will prepend the base dir
             subfilePath << *filename << ".parallel/mpi_rank_"
                         << std::setw(num_digits(size - 1)) << std::setfill('0')
-                        << rank << ".json";
+                        << rank << [&]() {
+                               switch (m_fileFormat)
+                               {
+                               case FileFormat::Json:
+                                   return ".json";
+                               case FileFormat::Toml:
+                                   return ".toml";
+                               }
+                               throw std::runtime_error("Unreachable!");
+                           }();
             writeSingleFile(subfilePath.str());
             if (rank == 0)
             {