Create the FilesystemWatcherInterface directly in the LibraryWatcher, fixing a crash when trying to add a new device.

src/library/library.cpp

@@ -20,7 +20,6 @@
 #include "librarymodel.h"
 #include "librarybackend.h"
 #include "core/database.h"
-#include "core/filesystemwatcherinterface.h"
 #include "smartplaylists/generator.h"
 #include "smartplaylists/querygenerator.h"
 #include "smartplaylists/search.h"
@@ -121,7 +120,6 @@ void Library::WatcherInitialised() {
 
   watcher->set_backend(backend_);
   watcher->set_task_manager(task_manager_);
-  watcher->set_filesystem_watcher(FileSystemWatcherInterface::Create());
 
   connect(backend_, SIGNAL(DirectoryDiscovered(Directory,SubdirectoryList)),
           watcher,  SLOT(AddDirectory(Directory,SubdirectoryList)));

src/library/librarywatcher.cpp

@@ -49,7 +49,7 @@ LibraryWatcher::LibraryWatcher(QObject* parent)
   : QObject(parent),
     backend_(NULL),
     task_manager_(NULL),
-    fs_watcher_(NULL),
+    fs_watcher_(FileSystemWatcherInterface::Create(this)),
     stop_requested_(false),
     scan_on_startup_(true),
     monitor_(true),
@@ -695,9 +695,7 @@ void LibraryWatcher::ReloadSettings() {
   }
 
   if (!monitor_ && was_monitoring_before) {
-    if (fs_watcher_) {
-      fs_watcher_->Clear();
-    }
+    fs_watcher_->Clear();
   } else if (monitor_ && !was_monitoring_before) {
     // Add all directories to all QFileSystemWatchers again
     foreach (const DirData& data, watched_dirs_.values()) {

src/library/librarywatcher.h

@@ -44,7 +44,6 @@ class LibraryWatcher : public QObject {
 
   void set_backend(LibraryBackend* backend) { backend_ = backend; }
   void set_task_manager(TaskManager* task_manager) { task_manager_ = task_manager; }
-  void set_filesystem_watcher(FileSystemWatcherInterface* watcher) { fs_watcher_ = watcher; }
   void set_device_name(const QString& device_name) { device_name_ = device_name; }
 
   void IncrementalScanAsync();