Add parent + explicit

src/foldershortcutactionmanager.h

@@ -23,7 +23,7 @@ class FolderShortcutCommand : public QObject
     Q_OBJECT
 
 public:
-    FolderShortcutCommand(QWidget *mainwidget, const Akonadi::Collection &col);
+    explicit FolderShortcutCommand(QWidget *mainwidget, const Akonadi::Collection &col);
     ~FolderShortcutCommand() override;
 
 public Q_SLOTS:

src/mailserviceimpl.cpp

@@ -20,7 +20,8 @@
 #include <QDBusConnection>
 
 using namespace KMail;
-MailServiceImpl::MailServiceImpl()
+MailServiceImpl::MailServiceImpl(QObject *parent)
+    : QObject(parent)
 {
     new ServiceAdaptor(this);
     QDBusConnection::sessionBus().registerObject(QStringLiteral("/MailTransportService"), this);

src/mailserviceimpl.h

@@ -20,7 +20,7 @@ class MailServiceImpl : public QObject
 {
     Q_OBJECT
 public:
-    MailServiceImpl();
+    explicit MailServiceImpl(QObject *parent = nullptr);
     Q_REQUIRED_RESULT bool sendMessage(const QString &from,
                                        const QString &to,
                                        const QString &cc,