Extract logic to NoteDataUtil::StringInterpretsAs

src/NoteDataUtil.cpp

@@ -11,6 +11,17 @@
 #include "TimingData.h"
 #include <utility>
 
+bool NoteDataUtil::StringInterpretsAs( const std::string& str, int integer ) {
+	try
+	{
+		return std::stoi( str ) == integer;
+	}
+	catch ( const std::invalid_argument & )
+	{
+		return false;
+	}
+}
+
 // TODO: Remove these constants that aren't time signature-aware
 static const int BEATS_PER_MEASURE = 4;
 static const int ROWS_PER_MEASURE = ROWS_PER_BEAT * BEATS_PER_MEASURE;

src/NoteDataUtil.h

@@ -23,6 +23,11 @@ void LightTransformHelper( const NoteData &in, NoteData &out, const vector<int>
  * and makes it much easier to change NoteData internally in the future. */
 namespace NoteDataUtil
 {
+	/**
+	 * @brief Whether a string can be interpreted as the provided signed integer
+	 */
+	bool StringInterpretsAs( const std::string& str, int integer );
+
 	NoteType GetSmallestNoteTypeForMeasure( const NoteData &nd, int iMeasureIndex );
 	NoteType GetSmallestNoteTypeInRange( const NoteData &nd, int iStartIndex, int iEndIndex );
 	void LoadFromSMNoteDataString( NoteData &out, const RString &sSMNoteData, bool bComposite );

src/NotesLoaderSM.cpp

@@ -3,6 +3,7 @@
 #include "BackgroundUtil.h"
 #include "GameManager.h"
 #include "MsdFile.h"
+#include "NoteDataUtil.h"
 #include "NoteTypes.h"
 #include "RageFileManager.h"
 #include "RageLog.h"
@@ -974,58 +975,25 @@ bool SMLoader::LoadFromBGChangesVector( BackgroundChange &change, std::vector<RS
 	case 6:
 		// param 7 overrides this.
 		// Backward compatibility:
-		if( change.m_def.m_sEffect.empty() )
+		if( change.m_def.m_sEffect.empty() && !NoteDataUtil::StringInterpretsAs( aBGChangeValues[5], 0 ) )
 		{
-			try
+			change.m_def.m_sEffect = SBE_StretchNoLoop;
-			{
-				if( std::stoi( aBGChangeValues[5] ) != 0 )
-				{
-					change.m_def.m_sEffect = SBE_StretchNoLoop;
-				}
-			}
-			catch ( const std::invalid_argument & )
-			{
-				// Failed conversions mean it's not 0 as well
-				change.m_def.m_sEffect = SBE_StretchNoLoop;
-			}
 		}
 		// fall through
 	case 5:
 		// param 7 overrides this.
 		// Backward compatibility:
-		if( change.m_def.m_sEffect.empty() )
+		if( change.m_def.m_sEffect.empty() && !NoteDataUtil::StringInterpretsAs( aBGChangeValues[4], 0 ) )
 		{
-			try
+			change.m_def.m_sEffect = SBE_StretchRewind;
-			{
-				if( std::stoi( aBGChangeValues[4] ) != 0 )
-				{
-					change.m_def.m_sEffect = SBE_StretchRewind;
-				}
-			}
-			catch ( const std::invalid_argument & )
-			{
-				// Failed conversions mean it's not 0 as well
-				change.m_def.m_sEffect = SBE_StretchRewind;
-			}
 		}
 		// fall through
 	case 4:
 		// param 9 overrides this.
 		// Backward compatibility:
-		if( change.m_sTransition.empty() )
+		if( change.m_sTransition.empty() && !NoteDataUtil::StringInterpretsAs( aBGChangeValues[3], 0 ) )
 		{
-			try
+			change.m_sTransition = SBT_CrossFade;
-			{
-				if( std::stoi( aBGChangeValues[3] ) != 0 )
-				{
-					change.m_sTransition = SBT_CrossFade;
-				}
-			}
-			catch ( const std::invalid_argument & )
-			{
-				// Failed conversions mean it's not 0 as well
-				change.m_sTransition = SBT_CrossFade;
-			}
 		}
 		// fall through
 	case 3: