Changed ScreenSelectMusic and Song to look for preview.ogg and use it for a sample if it exists instead of the music file. Sample length still comes from simfile. Changed foreach_ordered to work on tables with string and number keys.

src/ScreenSelectMusic.cpp

@@ -1796,9 +1796,9 @@ void ScreenSelectMusic::AfterMusicChange()
 			case SampleMusicPreviewMode_Normal:
 			case SampleMusicPreviewMode_LastSong: // fall through
 				// play the sample music
-				m_sSampleMusicToPlay = pSong->GetMusicPath();
+				m_sSampleMusicToPlay = pSong->GetPreviewMusicPath();
 				m_pSampleMusicTimingData = &pSong->m_SongTiming;
-				m_fSampleStartSeconds = pSong->m_fMusicSampleStartSeconds;
+				m_fSampleStartSeconds = pSong->GetPreviewStartSeconds();
 				m_fSampleLengthSeconds = pSong->m_fMusicSampleLengthSeconds;
 				break;
 			default:

src/Song.cpp

@@ -1477,6 +1477,26 @@ RString Song::GetPreviewVidPath() const
 	return GetSongAssetPath( m_sPreviewVidFile, m_sSongDir );
 }
 
+RString Song::GetPreviewMusicPath() const
+{
+	RString preview= GetSongDir() + "preview.ogg";
+	if(FILEMAN->DoesFileExist(preview))
+	{
+		return preview;
+	}
+	return GetMusicPath();
+}
+
+float Song::GetPreviewStartSeconds() const
+{
+	RString preview= GetSongDir() + "preview.ogg";
+	if(FILEMAN->DoesFileExist(preview))
+	{
+		return 0.0f;
+	}
+	return m_fMusicSampleStartSeconds;
+}
+
 RString Song::GetDisplayMainTitle() const
 {
 	if(!PREFSMAN->m_bShowNativeLanguage) return GetTranslitMainTitle();

src/Song.h

@@ -257,6 +257,8 @@ public:
 	RString GetBackgroundPath() const;
 	RString GetCDTitlePath() const;
 	RString GetPreviewVidPath() const;
+	RString GetPreviewMusicPath() const;
+	float GetPreviewStartSeconds() const;
 
 	// For loading only:
 	bool m_bHasMusic, m_bHasBanner, m_bHasBackground;