Remove FileMonitorBlocker which does not work reliably on all platforms

src/Buffer.cpp

@@ -382,9 +382,6 @@ public:
 	/// Notify or clear of external modification
 	void fileExternallyModified(bool exists) const;
 
-	/// Block notifications of external modifications
-	FileMonitorBlocker blockFileMonitor() { return file_monitor_->block(); }
-
 	/// has been externally modified? Can be reset by the user.
 	mutable bool externally_modified_;
 
@@ -1379,7 +1376,6 @@ FileName Buffer::getBackupName() const {
 // Should probably be moved to somewhere else: BufferView? GuiView?
 bool Buffer::save() const
 {
-	FileMonitorBlocker block = d->blockFileMonitor();
 	docstring const file = makeDisplayPath(absFileName(), 20);
 	d->filename.refresh();
 
@@ -5338,8 +5334,7 @@ void Buffer::Impl::refreshFileMonitor()
 
 void Buffer::Impl::fileExternallyModified(bool const exists) const
 {
-	// prevent false positives, because FileMonitorBlocker is not enough on
+	// ignore notifications after our own saving operations
-	// OSX.
 	if (checksum_ == filename.checksum()) {
 		LYXERR(Debug::FILES, "External modification but "
 		       "checksum unchanged: " << filename);

src/support/FileMonitor.cpp

@@ -202,42 +202,6 @@ void FileMonitor::changed(bool const exists)
 }
 
 
-FileMonitorBlocker FileMonitor::block(int delay)
-{
-	FileMonitorBlocker blocker = blocker_.lock();
-	if (!blocker)
-		blocker_ = blocker = make_shared<FileMonitorBlockerGuard>(this);
-	blocker->setDelay(delay);
-	return blocker;
-}
-
-
-FileMonitorBlockerGuard::FileMonitorBlockerGuard(FileMonitor * monitor)
-	: monitor_(monitor), delay_(0)
-{
-	QObject::disconnect(monitor->monitor_.get(), SIGNAL(fileChanged(bool)),
-	                    monitor, SLOT(changed(bool)));
-}
-
-
-void FileMonitorBlockerGuard::setDelay(int delay)
-{
-	delay_ = max(delay_, delay);
-}
-
-
-FileMonitorBlockerGuard::~FileMonitorBlockerGuard()
-{
-	if (!monitor_)
-		return;
-	// Even if delay_ is 0, the QTimer is necessary. Indeed, the notifications
-	// from QFileSystemWatcher that we meant to ignore are not going to be
-	// treated immediately, so we must yield to give us the opportunity to
-	// ignore them.
-	QTimer::singleShot(delay_, monitor_, SLOT(connectToFileMonitorGuard()));
-}
-
-
 ActiveFileMonitor::ActiveFileMonitor(std::shared_ptr<FileMonitorGuard> monitor,
                                      FileName const & filename, int interval)
 	: FileMonitor(monitor), filename_(filename), interval_(interval),

src/support/FileMonitor.h

@@ -60,12 +60,6 @@ typedef std::unique_ptr<ActiveFileMonitor> ActiveFileMonitorPtr;
 ///   monitor.connect(...);
 /// (stops watching the first)
 ///
-/// Block notifications for the duration of a scope:
-///   {
-///       FileMonitorBlocker block = monitor.block();
-///       ...
-///   }
-///
 /// Reset connections:
 ///   monitor.disconnect();
 ///   or the disconnect method of the connection object for the boost signal.
@@ -131,27 +125,10 @@ private:
 };
 
 
-class FileMonitorBlockerGuard : public QObject
-{
-	Q_OBJECT
-	QPointer<FileMonitor> monitor_;
-	int delay_;
-
-public:
-	FileMonitorBlockerGuard(FileMonitor * monitor);
-	~FileMonitorBlockerGuard();
-	void setDelay(int delay);
-};
-
-
-typedef std::shared_ptr<FileMonitorBlockerGuard> FileMonitorBlocker;
-
-
 /// Main class
 class FileMonitor : public QObject
 {
 	Q_OBJECT
-	friend class FileMonitorBlockerGuard;
 
 public:
 	FileMonitor(std::shared_ptr<FileMonitorGuard> monitor);
@@ -165,20 +142,6 @@ public:
 	void disconnect();
 	/// absolute path being tracked
 	std::string const & filename() { return monitor_->filename(); }
-	/// Creates a guard that blocks notifications. Copyable. Notifications from
-	/// this monitor are blocked as long as there are copies of the
-	/// FileMonitorBlocker around.
-	/// \param delay is the amount waited in ms after expiration of the guard
-	/// before reconnecting. It can be used to slow down incoming events
-	/// accordingly. A value of 0 is still made asynchronous, because of the
-	/// fundamentally asynchronous nature of QFileSystemWatcher. To catch one's
-	/// own file operations, a value of 0 for delay is sufficient with the
-	/// inotify backend (e.g. Linux); for OSX (kqueue), a value of 100ms is
-	/// unsufficient and more tests need to be done in combination with
-	/// flushing/syncing to disk in order to understand how to catch one's own
-	/// operations reliably. No feedback about Windows. See
-	/// <https://www.mail-archive.com/lyx-devel@lists.lyx.org/msg200252.html>.
-	FileMonitorBlocker block(int delay = 0);
 	/// Make sure the good file is being monitored, after e.g. a move or a
 	/// deletion. See <https://bugreports.qt.io/browse/QTBUG-46483>. This is
 	/// called automatically.
@@ -199,8 +162,6 @@ private:
 	sig fileChanged_;
 	/// the unique watch for our file
 	std::shared_ptr<FileMonitorGuard> const monitor_;
-	///
-	std::weak_ptr<FileMonitorBlockerGuard> blocker_;
 };