On completion, calendar migration restores previous Akonadi run state

Changelog

 KAlarm Change Log
 
-=== Version 3.1.0 (KDE Applications 20.12) --- 28 October 2020 ===
+=== Version 3.1.0 (KDE Applications 20.12) --- 14 November 2020 ===
 + Add option to show alarm message as a notification instead of in a window [KDE Bug 345922]
 + Add option to give alarms a name.
 + Don't execute display alarms while desktop notifications are inhibited.
 + Cancel any screen saver when an alarm is displayed.
++ On completion, calendar migration restores previous Akonadi run state.
 
 === Version 3.0.3 (KDE Applications 20.08.3) --- 25 October 2020 ===
 + Prevent resources being disabled at logout [KDE Bug 427722]

src/resources/fileresourcemigrator.cpp

@@ -143,7 +143,9 @@ void FileResourceMigrator::start()
         mAkonadiMigration->required = true;
         connect(mAkonadiMigration, &FileResourceMigrator::AkonadiMigration::completed, this, &FileResourceMigrator::akonadiMigrationComplete);
         connect(Akonadi::ServerManager::self(), &Akonadi::ServerManager::stateChanged, this, &FileResourceMigrator::checkAkonadiResources);
-        checkAkonadiResources(Akonadi::ServerManager::state());
+        auto akstate = Akonadi::ServerManager::state();
+        mAkonadiStart = (akstate == Akonadi::ServerManager::NotRunning);
+        checkAkonadiResources(akstate);
         // Migration of Akonadi collections has now been initiated. On
         // completion, either KResource calendars will be migrated, or
         // any missing default resources will be created.
@@ -366,6 +368,17 @@ void FileResourceMigrator::collectionFetchResult(KJob* j)
 */
 void FileResourceMigrator::akonadiMigrationComplete()
 {
+    // Ignore any further Akonadi server state changes, to prevent possible
+    // repeated migrations.
+    disconnect(Akonadi::ServerManager::self(), nullptr, this, nullptr);
+
+    if (mAkonadiStart)
+    {
+        // The Akonadi server wasn't running before we started it, so stop it
+        // now that it's no longer needed.
+        Akonadi::ServerManager::stop();
+    }
+
     if (!mAkonadiMigration->required)
     {
         // There are no Akonadi resources, so migrate any KResources alarm

src/resources/fileresourcemigrator.h

@@ -64,6 +64,7 @@ private:
     QList<Akonadi::CollectionFetchJob*> mFetchesPending;  // pending collection fetch jobs for existing resources
     KAlarmCal::CalEvent::Types mExistingAlarmTypes {KAlarmCal::CalEvent::EMPTY};  // alarm types provided by existing non-Akonadi resources
     bool            mMigrateKResources {true};  // need to migrate KResource resources
+    bool            mAkonadiStart {false};      // Akonadi was started by the migrator
     static bool     mCompleted;                 // execute() has completed
 };