logic: allow the user to discard an aborted indexer run

* keep old database on filesystem while indexing
* migrate old ".coatiproject" settings to new ".srctrlprj" extension when loading project
* send new errors in MessageErrorCountUpdate after injecting
* recheck filepath exist() in FileSystem's remove, rename, copy and create functions
* updated tasks to new "override" policy

src/lib_gui/qt/view/QtDialogView.cpp

@@ -221,24 +221,50 @@ void QtDialogView::updateIndexingDialog(
 	);
 }
 
-void QtDialogView::finishedIndexingDialog(
+DatabasePolicy QtDialogView::finishedIndexingDialog(
 	size_t indexedFileCount, size_t totalIndexedFileCount, size_t completedFileCount, size_t totalFileCount,
 	float time, ErrorCountInfo errorInfo, bool interrupted)
 {
+	DatabasePolicy policy = DATABASE_POLICY_UNKNOWN;
+	m_resultReady = false;
 
 	m_onQtThread(
-		[=]()
+		[=, &policy]()
 		{
 			m_windowStack.clearWindows();
 
 			QtIndexingDialog* window = createWindow<QtIndexingDialog>();
 			window->setupReport(indexedFileCount, totalIndexedFileCount, completedFileCount, totalFileCount, time, interrupted);
 			window->updateErrorCount(errorInfo.total, errorInfo.fatal);
+			connect(window, &QtWindow::finished,
+				[this, &policy]()
+				{
+					setUIBlocked(false);
+					policy = DATABASE_POLICY_KEEP;
+					m_resultReady = true;
+				}
+			);
+			connect(window, &QtWindow::canceled,
+				[this, &policy]()
+				{
+					setUIBlocked(false);
+					policy = DATABASE_POLICY_DISCARD;
+					m_resultReady = true;
+				}
+			);
 
-			setUIBlocked(false);
 			m_mainWindow->hideWindowsTaskbarProgress();
+			setUIBlocked(true);
 		}
 	);
+
+	while (!m_resultReady)
+	{
+		const int SLEEP_TIME_MS = 25;
+		std::this_thread::sleep_for(std::chrono::milliseconds(SLEEP_TIME_MS));
+	}
+
+	return policy;
 }
 
 void QtDialogView::hideDialogs(bool unblockUI)

src/lib_gui/qt/view/QtDialogView.h

@@ -25,26 +25,26 @@ class QtDialogView
 
 public:
 	QtDialogView(QtMainWindow* mainWindow, StorageAccess* storageAccess);
-	virtual ~QtDialogView();
+	~QtDialogView() override;
 
-	virtual void showUnknownProgressDialog(const std::wstring& title, const std::wstring& message) override;
-	virtual void hideUnknownProgressDialog() override;
+	void showUnknownProgressDialog(const std::wstring& title, const std::wstring& message) override;
+	void hideUnknownProgressDialog() override;
 
-	virtual void showProgressDialog(const std::wstring& title, const std::wstring& message, size_t progress) override;
-	virtual void hideProgressDialog() override;
+	void showProgressDialog(const std::wstring& title, const std::wstring& message, size_t progress) override;
+	void hideProgressDialog() override;
 
-	virtual void startIndexingDialog(
+	void startIndexingDialog(
 		Project* project, const std::vector<RefreshMode>& enabledModes, const RefreshInfo& info) override;
-	virtual void updateIndexingDialog(
+	void updateIndexingDialog(
 		size_t startedFileCount, size_t finishedFileCount, size_t totalFileCount, const FilePath& sourcePath) override;
-	virtual void finishedIndexingDialog(
+	DatabasePolicy finishedIndexingDialog(
 		size_t indexedFileCount, size_t totalIndexedFileCount, size_t completedFileCount, size_t totalFileCount,
 		float time, ErrorCountInfo errorInfo, bool interrupted) override;
 
-	virtual void hideDialogs(bool unblockUI = true) override;
+	void hideDialogs(bool unblockUI = true) override;
 
-	virtual int confirm(const std::string& message, const std::vector<std::string>& options) override;
-	virtual int confirm(const std::wstring& message, const std::vector<std::wstring>& options) override;
+	int confirm(const std::string& message, const std::vector<std::string>& options) override;
+	int confirm(const std::wstring& message, const std::vector<std::wstring>& options) override;
 
 	void setParentWindow(QtWindow* window);
 

src/lib_gui/qt/window/QtIndexingDialog.cpp

@@ -207,8 +207,16 @@ void QtIndexingDialog::setupReport(
 	layout->addStretch();
 
 	addButtons(layout);
-	updateNextButton("OK");
-	setCloseVisible(false);
+	if (interrupted)
+	{
+		updateNextButton("Keep");
+		updateCloseButton("Discard");
+	}
+	else
+	{
+		updateNextButton("OK");
+		setCloseVisible(false);
+	}
 
 	m_sizeHint = QSize(interrupted ? 400 : 430, 280);