Don't modify stored courses; it's far too easy to accidentally forget

to reset them in one of the (many) exit-gameplay paths, or reset it
incorrectly.

This fixes the course selection screen crashing when there is
no music.

stepmania/src/Course.cpp

@@ -22,6 +22,8 @@
 #include "SongOptions.h"
 #include "RageUtil.h"
 #include "TitleSubstitution.h"
+#include "Notes.h"
+#include "GameState.h"
 
 
 Course::Course()
@@ -431,10 +433,26 @@ void Course::GetStageInfo(
 		if( !pSong || !pNotes )
 			continue;	// this song entry isn't playable.  Skip.
 
+		if(GAMESTATE->m_bDifficultCourses)
+		{
+			/* See if we can find a NoteData that's one notch more difficult than
+			 * the one we found above. */
+			Difficulty dc = pNotes->GetDifficulty();
+			if(dc < DIFFICULTY_CHALLENGE)
+			{
+				dc  = Difficulty(dc + 1);
+				Notes* pNewNotes = pSong->GetNotes( nt, dc );
+				if(pNewNotes)
+					pNotes = pNewNotes;
+			}
+		}
+
 		vSongsOut.push_back( pSong ); 
 		vNotesOut.push_back( pNotes ); 
 		vsModifiersOut.push_back( e.modifiers );
 	}
+
+
 }
 
 bool Course::GetFirstStageInfo(
@@ -609,41 +627,6 @@ void Course::AddScores( NotesType nt, bool bPlayerEnabled[NUM_PLAYERS], int iDan
 	}
 }
 
-bool Course::MakeNormal()
-{
-	if( !m_bRepeat && m_iLives == -1 ) // nonstop only, not oni or endless
-		if(m_bDifficult) //only make it easy if it's already difficult
-		{
-			unsigned c;
-			for( c = 0; c < m_entries.size(); c++)
-			{
-				if( m_entries[c].difficulty == DIFFICULTY_BEGINNER || m_entries[c].difficulty == DIFFICULTY_INVALID ) // don't suddenly make things invalid or worse
-					continue;
-
-				m_entries[c].difficulty = Difficulty(m_entries[c].difficulty - 1);
-			}
-			m_bDifficult = false;
-			return true;
-		}
-	return false;
-}
-bool Course::MakeDifficult()
-{
-	if( !m_bRepeat && m_iLives == -1 ) // nonstop only, not oni or endless
-		if(!m_bDifficult) //only make it difficult once
-		{
-			unsigned c;
-			for( c = 0; c < m_entries.size(); c++)
-			{
-				if( m_entries[c].difficulty < DIFFICULTY_CHALLENGE ) // don't suddenly make things invalid or worse
-					m_entries[c].difficulty = Difficulty(m_entries[c].difficulty + 1);
-			}
-			m_bDifficult = true;
-			return true;
-		}
-	return false;
-}
-
 
 //
 // Sorting stuff

stepmania/src/Course.h

@@ -76,8 +76,6 @@ public:
 	void GetMeterRange( int stage, int& iMeterLowOut, int& iMeterHighOut ) const;
 	bool ContainsAnyMysterySongs() const;
 	bool GetTotalSeconds( float& fSecondsOut ) const;
-	bool MakeDifficult();
-	bool MakeNormal();
 
 
 	void LoadFromCRSFile( CString sPath );

stepmania/src/MusicWheel.cpp

@@ -844,9 +844,6 @@ void MusicWheel::Update( float fDeltaTime )
 
 void MusicWheel::ChangeMusic(int dist)
 {
-	if(GAMESTATE->m_PlayMode == PLAY_MODE_NONSTOP)
-		GetSelectedCourse()->MakeNormal();
-
 	m_iSelection += dist;
 	if( m_iSelection < 0 )
 		m_iSelection = m_CurWheelItemData.size()-1;
@@ -857,9 +854,6 @@ void MusicWheel::ChangeMusic(int dist)
 
 	m_fPositionOffsetFromSelection += dist;
 
-	if(GAMESTATE->m_bDifficultCourses && GAMESTATE->m_PlayMode == PLAY_MODE_NONSTOP)
-		GetSelectedCourse()->MakeDifficult();
-
 	SCREENMAN->PostMessageToTopScreen( SM_SongChanged, 0 );
 
 	/* If we're moving automatically, don't play this; it'll be called in Update. */

stepmania/src/ScreenSelectCourse.cpp

@@ -253,24 +253,20 @@ void ScreenSelectCourse::Input( const DeviceInput& DeviceI, InputEventType type,
 		return;
 	}
 
-	if( CodeDetector::EnteredEasierDifficulty(GameI.controller) )
+	if( CodeDetector::EnteredEasierDifficulty(GameI.controller) &&
+		GAMESTATE->m_bDifficultCourses)
 	{
-		if( m_MusicWheel.GetSelectedCourse()->MakeNormal() )
-		{
-			m_soundChangeNotes.Play();
-			GAMESTATE->m_bDifficultCourses = false;
-			SCREENMAN->PostMessageToTopScreen(SM_SongChanged,0);
-		}	
+		m_soundChangeNotes.Play();
+		GAMESTATE->m_bDifficultCourses = false;
+		SCREENMAN->PostMessageToTopScreen(SM_SongChanged,0);
 	}
 
-	if( CodeDetector::EnteredHarderDifficulty(GameI.controller) )
+	if( CodeDetector::EnteredHarderDifficulty(GameI.controller) &&
+		!GAMESTATE->m_bDifficultCourses)
 	{
-		if( m_MusicWheel.GetSelectedCourse()->MakeDifficult() )
-		{
-			m_soundChangeNotes.Play();
-			GAMESTATE->m_bDifficultCourses = true;
-			SCREENMAN->PostMessageToTopScreen(SM_SongChanged,0);
-		}	
+		m_soundChangeNotes.Play();
+		GAMESTATE->m_bDifficultCourses = true;
+		SCREENMAN->PostMessageToTopScreen(SM_SongChanged,0);
 	}