Fix re-connect when process status is considered and Syncthing restarted

When Syncthing restarts itself, its main process is not terminating (as its
main process is just a monitoring process). The "Consider process status …"
feature was relying on the process being stopped and started again as
trigger for trying to re-connect, though. To make it also work when
Syncthing restarts itself, this change checks the log for an exiting
message of the monitoring process and considers the process running again
when the GUI address is logged again.

This fixes #236.

Notifications are not (yet) suppressed. (Not sure how easy it is and how
much sense it makes.)

syncthingwidgets/misc/syncthinglauncher.cpp

@@ -45,6 +45,8 @@ SyncthingLauncher::SyncthingLauncher(QObject *parent)
     , m_relevantConnection(nullptr)
     , m_guiListeningUrlSearch("Access the GUI via the following URL: ", "\n\r", std::string_view(),
           std::bind(&SyncthingLauncher::handleGuiListeningUrlFound, this, std::placeholders::_1, std::placeholders::_2))
+    , m_exitSearch("Syncthing exited: ", "\n\r", std::string_view(),
+          std::bind(&SyncthingLauncher::handleExitFound, this, std::placeholders::_1, std::placeholders::_2))
 #ifdef SYNCTHINGWIDGETS_USE_LIBSYNCTHING
     , m_libsyncthingLogLevel(LibSyncthing::LogLevel::Info)
 #endif
@@ -332,19 +334,31 @@ void SyncthingLauncher::handleLoggingCallback(LibSyncthing::LogLevel level, cons
 void SyncthingLauncher::handleOutputAvailable(QByteArray &&data)
 {
     m_guiListeningUrlSearch(data.data(), static_cast<std::size_t>(data.size()));
+    m_exitSearch(data.data(), static_cast<std::size_t>(data.size()));
     if (isEmittingOutput()) {
         emit outputAvailable(data);
     } else {
         m_outputBuffer += data;
     }
 }
 
-void SyncthingLauncher::handleGuiListeningUrlFound(CppUtilities::BufferSearch &, std::string &&searchResult)
+void SyncthingLauncher::handleGuiListeningUrlFound(CppUtilities::BufferSearch &search, std::string &&searchResult)
 {
     m_guiListeningUrl.setUrl(QString::fromStdString(searchResult));
+    std::cerr << EscapeCodes::Phrases::Info << "Syncthing GUI available: " << searchResult << EscapeCodes::Phrases::End;
+    search.reset();
     emit guiUrlChanged(m_guiListeningUrl);
 }
 
+void SyncthingLauncher::handleExitFound(CppUtilities::BufferSearch &search, std::string &&searchResult)
+{
+    m_guiListeningUrl.clear();
+    std::cerr << EscapeCodes::Phrases::Info << "Syncthing exited: " << searchResult << EscapeCodes::Phrases::End;
+    emit guiUrlChanged(m_guiListeningUrl);
+    emit exitLogged(std::move(searchResult));
+    search.reset();
+}
+
 void SyncthingLauncher::terminateDueToMeteredConnection()
 {
     if (!isRunning()) {
@@ -366,6 +380,8 @@ void SyncthingLauncher::runLibSyncthing(const LibSyncthing::RuntimeOptions &runt
     LibSyncthing::setLoggingCallback(bind(&SyncthingLauncher::handleLoggingCallback, this, _1, _2, _3));
     emit runningChanged(true);
     const auto exitCode = LibSyncthing::runSyncthing(runtimeOptions);
+    m_guiListeningUrl.clear();
+    emit guiUrlChanged(m_guiListeningUrl);
     emit exited(static_cast<int>(exitCode), exitCode == 0 ? QProcess::NormalExit : QProcess::CrashExit);
     emit runningChanged(false);
 }

syncthingwidgets/misc/syncthinglauncher.h

@@ -70,6 +70,7 @@ class SYNCTHINGWIDGETS_EXPORT SyncthingLauncher : public QObject {
     void confirmKill();
     void runningChanged(bool isRunning);
     void outputAvailable(const QByteArray &data);
+    void exitLogged(const std::string &exitMessage);
     void exited(int exitCode, QProcess::ExitStatus exitStatus);
     void errorOccurred(QProcess::ProcessError error);
     void guiUrlChanged(const QUrl &newUrl);
@@ -99,7 +100,8 @@ private Q_SLOTS:
     void handleLoggingCallback(LibSyncthing::LogLevel, const char *message, std::size_t messageSize);
 #endif
     void handleOutputAvailable(QByteArray &&data);
-    void handleGuiListeningUrlFound(CppUtilities::BufferSearch &bufferSearch, std::string &&searchResult);
+    void handleGuiListeningUrlFound(CppUtilities::BufferSearch &search, std::string &&searchResult);
+    void handleExitFound(CppUtilities::BufferSearch &search, std::string &&searchResult);
     void terminateDueToMeteredConnection();
 
     SyncthingProcess m_process;
@@ -110,6 +112,7 @@ private Q_SLOTS:
     QFuture<void> m_stopFuture;
     QByteArray m_outputBuffer;
     CppUtilities::BufferSearch m_guiListeningUrlSearch;
+    CppUtilities::BufferSearch m_exitSearch;
     CppUtilities::DateTime m_futureStarted;
 #ifdef SYNCTHINGWIDGETS_USE_LIBSYNCTHING
     LibSyncthing::LogLevel m_libsyncthingLogLevel;

syncthingwidgets/settings/settings.cpp

@@ -238,7 +238,7 @@ Launcher::LauncherStatus Launcher::apply(
         return LauncherStatus{};
     }
     const auto isRelevant = connection.isLocal();
-    const auto isRunning = launcher->isRunning();
+    const auto isRunning = launcher->isRunning() && !launcher->guiUrl().isEmpty();
     const auto consideredForReconnect = considerForReconnect && isRelevant;
     connectAccordingToSettings(
         connection, currentConnectionSettings, *launcher, reconnectRequired, considerForReconnect, isRelevant, isRunning, consideredForReconnect);

tray/gui/traywidget.cpp

@@ -222,6 +222,7 @@ TrayWidget::TrayWidget(TrayMenu *parent)
     connect(m_ui->startStopPushButton, &QPushButton::clicked, this, &TrayWidget::toggleRunning);
     if (const auto *const launcher = SyncthingLauncher::mainInstance()) {
         connect(launcher, &SyncthingLauncher::runningChanged, this, &TrayWidget::handleLauncherStatusChanged);
+        connect(launcher, &SyncthingLauncher::guiUrlChanged, this, &TrayWidget::handleLauncherGuiAddressChanged);
     }
 #ifdef LIB_SYNCTHING_CONNECTOR_SUPPORT_SYSTEMD
     if (const auto *const service = SyncthingService::mainInstance()) {
@@ -847,6 +848,16 @@ Settings::Launcher::LauncherStatus TrayWidget::handleLauncherStatusChanged()
     return launcherStatus;
 }
 
+Settings::Launcher::LauncherStatus TrayWidget::handleLauncherGuiAddressChanged(const QUrl &guiAddress)
+{
+    Q_UNUSED(guiAddress)
+#ifdef LIB_SYNCTHING_CONNECTOR_SUPPORT_SYSTEMD
+    return applyLauncherSettings(false, Settings::values().systemd.considerForReconnect, true);
+#else
+    return applyLauncherSettings(false);
+#endif
+}
+
 Settings::Launcher::LauncherStatus TrayWidget::applyLauncherSettings(bool reconnectRequired, bool skipApplyingToConnection, bool skipStartStopButton)
 {
     // update connection

tray/gui/traywidget.h

@@ -105,6 +105,7 @@ private Q_SLOTS:
     void updateIconAndTooltip();
     void toggleRunning();
     Settings::Launcher::LauncherStatus handleLauncherStatusChanged();
+    Settings::Launcher::LauncherStatus handleLauncherGuiAddressChanged(const QUrl &guiAddress);
     Settings::Launcher::LauncherStatus applyLauncherSettings(
         bool reconnectRequired = false, bool skipApplyingToConnection = false, bool skipStartStopButton = false);
 #ifdef LIB_SYNCTHING_CONNECTOR_SUPPORT_SYSTEMD