Don't delete timeline preview files on project close

src/project/projectmanager.cpp

@@ -240,6 +240,7 @@ bool ProjectManager::closeCurrentDocument(bool saveChanges, bool quit)
         }
     }
     pCore->window()->getMainTimeline()->controller()->clipActions.clear();
+    pCore->window()->getMainTimeline()->controller()->prepareClose();
     if (m_mainTimelineModel) {
         m_mainTimelineModel->prepareClose();
     }

src/timeline2/view/previewmanager.cpp

@@ -546,7 +546,6 @@ void PreviewManager::doPreviewRender(const QString &scene)
                      m_consumerParams.join(QLatin1Char(' '))};
     qDebug() << " -  - -STARTING PREVIEW JOBS: " << args;
     pCore->currentDoc()->previewProgress(0);
-    m_previewProcess.start(m_renderer, args);
     QObject::connect(&m_previewProcess, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished), [this, scene](int, QProcess::ExitStatus status) {
         qDebug() << "// PROCESS IS FINISHED!!!";
         QFile::remove(scene);
@@ -565,6 +564,7 @@ void PreviewManager::doPreviewRender(const QString &scene)
         workingPreview = -1;
         m_controller->workingPreviewChanged();
     });
+    m_previewProcess.start(m_renderer, args);
     if (m_previewProcess.waitForStarted()) {
         qDebug() << " -  - -STARTING PREVIEW JOBS . . . STARTED";
     }

src/timeline2/view/timelinecontroller.cpp

@@ -82,6 +82,12 @@ TimelineController::TimelineController(QObject *parent)
 
 TimelineController::~TimelineController()
 {
+    prepareClose();
+}
+
+void TimelineController::prepareClose()
+{
+    // Delete timeline preview before resetting model so that removing clips from timeline doesn't invalidate
     delete m_timelinePreview;
     m_timelinePreview = nullptr;
 }

src/timeline2/view/timelinecontroller.h

@@ -450,6 +450,8 @@ public:
     QStringList getThumbKeys();
     /** @brief Returns true if a drag operation is currently running in timeline */
     bool dragOperationRunning();
+    /** @brief Disconnect some stuff before closing project */
+    void prepareClose();
 
 public slots:
     void resetView();