From c38b55738edbf4745a2bb33052928454dde0ccb4 Mon Sep 17 00:00:00 2001
From: Laurent Montel <montel@kde.org>
Date: Sat, 26 Sep 2020 09:02:27 +0200
Subject: [PATCH] Don't store invalid format

---
 src/collectionpage/collectionviewwidget.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/collectionpage/collectionviewwidget.cpp b/src/collectionpage/collectionviewwidget.cpp
index 735512a..ee15cbe 100644
--- a/src/collectionpage/collectionviewwidget.cpp
+++ b/src/collectionpage/collectionviewwidget.cpp
@@ -184,8 +184,10 @@ void CollectionViewWidget::save(Akonadi::Collection &col)
     } else {
         qCDebug(MAILCOMMON_LOG) << "No settings defined";
     }
-    mFolderCollection->setFormatMessage(formatMessage);
-    mFolderCollection->writeConfig();
+    if (formatMessage != MessageViewer::Viewer::Unknown) {
+        mFolderCollection->setFormatMessage(formatMessage);
+        mFolderCollection->writeConfig();
+    }
 }
 
 void CollectionViewWidget::slotSelectFolderAggregation()