Fix compilation warnings about QFile::open

src/libneochat/neochatconnection.cpp

@@ -533,7 +533,11 @@ KeyImport::Error NeoChatConnection::exportMegolmSessions(const QString &passphra
     }
     QUrl url(path);
     QFile file(url.toLocalFile());
-    file.open(QFile::WriteOnly);
+    auto ok = file.open(QFile::WriteOnly);
+    if (!ok) {
+        qWarning() << "Failed to open" << file.fileName() << file.errorString();
+        return KeyImport::OtherError;
+    }
     file.write(result.value());
     file.close();
     return KeyImport::Success;

src/libneochat/neochatroom.cpp

@@ -261,7 +261,10 @@ QCoro::Task<void> NeoChatRoom::doUploadFile(QUrl url, QString body, std::optiona
 
         QTemporaryFile file;
         file.setFileTemplate(QStringLiteral("XXXXXX.jpg"));
-        file.open();
+        auto ok = file.open();
+        if (!ok) {
+            qWarning() << "Failed to open" << file.fileName() << file.errorString();
+        }
 
         const auto thumbnailImage = sink.videoFrame().toImage();
         Q_UNUSED(thumbnailImage.save(file.fileName()))

src/messagecontent/models/messagecontentmodel.h

@@ -189,7 +189,11 @@ private:
                 }
 
                 QFile file(fileTransferInfo.localPath.path());
-                file.open(QIODevice::ReadOnly);
+                auto ok = file.open(QIODevice::ReadOnly);
+                if (!ok) {
+                    qWarning() << "Failed to open" << fileTransferInfo.localPath.path() << file.errorString();
+                }
+
                 beginInsertRows({}, std::distance(m_components.begin(), it) + 1, std::distance(m_components.begin(), it) + 1);
                 it = m_components.insert(it + 1, MessageComponent{MessageComponentType::Code,  QString::fromStdString(file.readAll().toStdString()), {{u"class"_s, definitionForFile.name()}}});
                 endInsertRows();