[pim/trojita] src: Check that QFile is open before writing

Git commit 7ce96cc4b667aa53d7d92b385cb715361e2a1997 by Espen Sandøy Hustad.
Committed on 03/08/2026 at 19:02.
Pushed by ehustad into branch 'master'.

Check that QFile is open before writing

Show an error message if opening failed, and reset
the menu checkbox.

Fix src/Common/FileLogger.cpp:44:9: warning: ignoring return
value of function declared with 'nodiscard' attribute [-Wunused-result]

M  +9    -1    src/Common/FileLogger.cpp
M  +14   -7    src/Gui/ProtocolLoggerWidget.cpp

https://invent.kde.org/pim/trojita/-/commit/7ce96cc4b667aa53d7d92b385cb715361e2a1997

diff --git a/src/Common/FileLogger.cpp b/src/Common/FileLogger.cpp
index 5490f8742..6d45a7571 100644
--- a/src/Common/FileLogger.cpp
+++ b/src/Common/FileLogger.cpp
@@ -23,6 +23,7 @@
 #include <QDateTime>
 #include <QDebug>
 #include <QFile>
+#include <stdexcept>
 #include "FileLogger.h"
 
 namespace Common
@@ -45,7 +46,14 @@ void FileLogger::setFileLogging(const bool enabled, const QString &fileName)
     }
 
     auto logFile = std::make_unique<QFile>(fileName, nullptr);
-    logFile->open(QIODevice::Truncate | QIODevice::WriteOnly);
+    if (!logFile->open(QIODevice::Truncate | QIODevice::WriteOnly)) {
+        //: Translators: %1 is the filename of the logfile
+        //: %2 is the detailed error description from Qt, ready for human consumption
+        throw std::runtime_error(tr("Failed to open logfile \"%1\" for writing: %2")
+                                    .arg(fileName, logFile->errorString()).toStdString());
+        return;
+    }
+
     m_fileLog = LogFilePtr(new QTextStream(logFile.release()));
 }
 
diff --git a/src/Gui/ProtocolLoggerWidget.cpp b/src/Gui/ProtocolLoggerWidget.cpp
index c470ac22d..a65237f7c 100644
--- a/src/Gui/ProtocolLoggerWidget.cpp
+++ b/src/Gui/ProtocolLoggerWidget.cpp
@@ -29,6 +29,7 @@
 #include <QTimer>
 #include <QVBoxLayout>
 #include "ProtocolLoggerWidget.h"
+#include "Util.h"
 #include "Common/FileLogger.h"
 #include "Imap/Model/Utils.h"
 
@@ -62,15 +63,21 @@ void ProtocolLoggerWidget::slotSetPersistentLogging(const bool enabled)
 {
     if (enabled == !!m_fileLogger)
         return;
-
-    if (enabled) {
-        Q_ASSERT(!m_fileLogger);
-        m_fileLogger.reset(new Common::FileLogger(nullptr));
-        m_fileLogger->setFileLogging(true, Imap::Mailbox::persistentLogFileName());
-        m_fileLogger->setAutoFlush(true);
-    } else {
+    try {
+        if (enabled) {
+            Q_ASSERT(!m_fileLogger);
+            m_fileLogger.reset(new Common::FileLogger(nullptr));
+            m_fileLogger->setFileLogging(true, Imap::Mailbox::persistentLogFileName());
+            m_fileLogger->setAutoFlush(true);
+        } else {
+            m_fileLogger.reset();
+        }
+    }
+    catch (std::runtime_error &err) {
+        Util::messageBoxCritical(this, tr("Failed to open file"), QString::fromStdString(err.what()));
         m_fileLogger.reset();
     }
+
     emit persistentLoggingChanged(!!m_fileLogger);
 }