Track whether setup detection has already been started and avoid running it twice

This makes the code more explicit about avoiding triggering the setup
detection twice. Maybe it fixes
https://github.com/Martchus/syncthingtray/issues/174 but likely it does not
change the behavior (in general).

widgets/settings/setupdetection.cpp

@@ -98,10 +98,15 @@ void SetupDetection::reset()
     launcherExitStatus.reset();
     launcherError.reset();
     launcherOutput.clear();
+    m_testStarted = false;
 }
 
 void SetupDetection::startTest()
 {
+    if (m_testStarted) {
+        return;
+    }
+    m_testStarted = true;
     restoreConfig();
     initConnection();
     connection.reconnect();
@@ -141,8 +146,12 @@ void SetupDetection::handleTimeout()
 
 void SetupDetection::checkDone()
 {
+    if (!m_testStarted) {
+        return;
+    }
     if (isDone()) {
         timeout.stop();
+        m_testStarted = false;
         emit done();
     }
 }

widgets/settings/setupdetection.h

@@ -67,6 +67,9 @@ public:
     bool timedOut = false;
     bool configOk = false;
     bool autostartEnabled = false;
+
+private:
+    bool m_testStarted = false;
 };
 
 } // namespace QtGui

widgets/settings/wizard.cpp

@@ -532,7 +532,6 @@ void DetectionWizardPage::initializePage()
     }
 
     m_setupDetection->reset();
-    connect(m_setupDetection, &SetupDetection::done, this, &DetectionWizardPage::continueIfDone);
     emit completeChanged();
     QTimer::singleShot(0, this, &DetectionWizardPage::tryToConnect);
 }
@@ -591,6 +590,7 @@ void DetectionWizardPage::tryToConnect()
     }
 
     // start setup detection tests
+    connect(m_setupDetection, &SetupDetection::done, this, &DetectionWizardPage::continueIfDone, Qt::QueuedConnection);
     m_setupDetection->startTest();
 }