several code clean-ups and corrections

src/helpers.cpp

@@ -136,8 +136,8 @@ bool ParseArgv(vector<string> &v)
 		else if (*it == "volume")
 		{
 			it++;
-			Mpd->GetStatus();
+			Mpd->UpdateStatus();
-			if (Mpd->CheckForErrors())
+			if (!Mpd->GetErrorMessage().empty())
 			{
 				cout << "Error: " << Mpd->GetErrorMessage() << endl;
 				return 1;
@@ -151,7 +151,7 @@ bool ParseArgv(vector<string> &v)
 			cout << "ncmpcpp: invalid option " << *it << endl;
 			return 1;
 		}
-		if (Mpd->CheckForErrors())
+		if (!Mpd->GetErrorMessage().empty())
 		{
 			cout << "Error: " << Mpd->GetErrorMessage() << endl;
 			return 1;

src/mpdpp.cpp

@@ -119,20 +119,15 @@ void MPDConnection::SetErrorHandler(ErrorHandler handler, void *data)
 	itsErrorHandlerUserdata = data;
 }
 
-void MPDConnection::GetStatus()
+void MPDConnection::UpdateStatus()
 {
+	CheckForErrors();
+	
 	if (itsOldStatus)
 		mpd_freeStatus(itsOldStatus);
 	itsOldStatus = itsCurrentStatus;
 	mpd_sendStatusCommand(itsConnection);
 	itsCurrentStatus = mpd_getStatus(itsConnection);
-}
-
-void MPDConnection::UpdateStatus()
-{
-	CheckForErrors();
-	
-	GetStatus();
 	
 	if (!itsMaxPlaylistLength)
 		itsMaxPlaylistLength = GetPlaylistLength();
@@ -140,14 +135,16 @@ void MPDConnection::UpdateStatus()
 	if (CheckForErrors())
 		return;
 	
-	MPDStatusChanges changes;
-	
 	if (itsOldStats)
 		mpd_freeStats(itsOldStats);
 	itsOldStats = itsCurrentStats;
 	mpd_sendStatsCommand(itsConnection);
 	itsCurrentStats = mpd_getStats(itsConnection);
 	
+	if (itsCurrentStatus && itsUpdater)
+	{
+		MPDStatusChanges changes;
+		
 		if (itsOldStatus == NULL)
 		{
 			changes.Playlist = 1;
@@ -174,9 +171,9 @@ void MPDConnection::UpdateStatus()
 			changes.Repeat = itsOldStatus->repeat != itsCurrentStatus->repeat;
 			changes.PlayerState = itsOldStatus->state != itsCurrentStatus->state;
 		}
-	if (itsUpdater)
 		itsUpdater(this, changes, itsErrorHandlerUserdata);
 	}
+}
 
 void MPDConnection::UpdateDirectory(const string &path) const
 {

src/mpdpp.h

@@ -90,7 +90,6 @@ class MPDConnection
 		
 		void SetStatusUpdater(StatusUpdater, void *);
 		void SetErrorHandler(ErrorHandler, void *);
-		void GetStatus();
 		void UpdateStatus();
 		void UpdateDirectory(const string &) const;
 		
@@ -122,7 +121,7 @@ class MPDConnection
 		int GetPlaylistLength() const { return isConnected && itsCurrentStatus ? itsCurrentStatus->playlistLength : 0; }
 		void GetPlaylistChanges(long long, SongList &) const;
 		
-		string GetErrorMessage() const { return itsErrorMessage; }
+		const string & GetErrorMessage() const { return itsErrorMessage; }
 		int GetErrorCode() const { return itsErrorCode; }
 		
 		Song GetCurrentSong() const;
@@ -171,10 +170,9 @@ class MPDConnection
 		void GetSongs(const string &, SongList &) const;
 		void GetDirectories(const string &, TagList &) const;
 		
-		int CheckForErrors();
-		
 	private:
 		void ClearQueue();
+		int CheckForErrors();
 		
 		mpd_Connection *itsConnection;
 		bool isConnected;

src/status_checker.cpp

@@ -319,15 +319,16 @@ void NcmpcppStatusChanged(MPDConnection *Mpd, MPDStatusChanges changed, void *)
 		playing_song_scroll_begin = 0;
 		
 		if (Mpd->GetState() == psPlay)
+		{
+			WindowTitle(DisplaySong(Mpd->GetCurrentSong(), &Config.song_window_title_format));
 			changed.ElapsedTime = 1;
 		}
+	}
 	if (changed.ElapsedTime)
 	{
-		Song s = Mpd->GetCurrentSong();
+		const Song &s = Mpd->GetCurrentSong();
 		if (!player_state.empty() && !s.Empty())
 		{
-			WindowTitle(DisplaySong(s, &Config.song_window_title_format));
-			
 			int elapsed = Mpd->GetElapsedTime();
 			
 			// 'repeat one' mode check - be sure that we deal with item with known length
@@ -391,14 +392,14 @@ void NcmpcppStatusChanged(MPDConnection *Mpd, MPDStatusChanges changed, void *)
 	if (changed.Repeat)
 	{
 		mpd_repeat = (Mpd->GetRepeat() ? "r" : "");
-		ShowMessage("Repeat is " + (string)(mpd_repeat.empty() ? "off" : "on"));
+		ShowMessage("Repeat is " + string(mpd_repeat.empty() ? "off" : "on"));
 		header_update_status = 1;
 
 	}
 	if (changed.Random)
 	{
 		mpd_random = Mpd->GetRandom() ? "z" : "";
-		ShowMessage("Random is " + (string)(mpd_random.empty() ? "off" : "on"));
+		ShowMessage("Random is " + string(mpd_random.empty() ? "off" : "on"));
 		header_update_status = 1;
 	}
 	if (changed.Crossfade)