return "" -> return NULL

stepmania/src/RageUtil.cpp

@@ -277,7 +277,7 @@ CString werr_ssprintf( int err, const char *fmt, ...)
 CString ConvertWstringToACP( wstring s )
 {
 	if( s.empty() )
-		return "";
+		return NULL;
 
 	int iBytes = WideCharToMultiByte( CP_ACP, 0, s.data(), s.size(), 
 					NULL, 0, NULL, FALSE );
@@ -301,7 +301,7 @@ CString ConvertUTF8ToACP( CString s )
 CString join( const CString &Deliminator, const CStringArray& Source)
 {
 	if( Source.empty() )
-		return "";
+		return NULL;
 
 	CString csTmp;
 
@@ -317,7 +317,7 @@ CString join( const CString &Deliminator, const CStringArray& Source)
 CString join( const CString &Delimitor, CStringArray::const_iterator begin, CStringArray::const_iterator end )
 {
 	if( begin == end )
-		return "";
+		return NULL;
 
 	CString ret;
 	while( begin != end )
@@ -512,11 +512,11 @@ CString GetExtension( const CString &sPath )
 {
 	size_t pos = sPath.rfind( '.' );
 	if( pos == sPath.npos )
-		return "";
+		return NULL;
 
 	size_t slash = sPath.find( '/', pos );
 	if( slash != sPath.npos )
-		return ""; /* rare: path/dir.ext/fn */
+		return NULL; /* rare: path/dir.ext/fn */
 
 	return sPath.substr( pos+1, sPath.size()-pos+1 );
 }
@@ -660,6 +660,15 @@ void StripCrnl(CString &s)
 		s.erase(s.size()-1);
 }
 
+bool EndsWith( const CString &sTestThis, const CString &sEnding )
+{
+	ASSERT( !sEnding.empty() );
+
+	if( sTestThis.size() < sEnding.size() )
+		return false;
+	return sTestThis.Right( sEnding.size() ) == sEnding;
+}
+
 void StripCvs( vector<CString> &vs )
 {
 	for( unsigned i=0; i<vs.size(); i++ )
@@ -686,7 +695,7 @@ CString DerefRedir(const CString &_path)
 
 		/* Empty is invalid. */
 		if( sNewFileName == "" )
-			return "";
+			return NULL;
 
 		FixSlashesInPlace( sNewFileName );
 
@@ -1244,7 +1253,7 @@ CString Basename( const CString &dir )
 {
 	size_t  end = dir.find_last_not_of( "/\\" );
 	if( end == dir.npos )
-		return "";
+		return NULL;
 
 	size_t  start = dir.find_last_of( "/\\", end );
 	if( start == dir.npos )
@@ -1286,7 +1295,7 @@ CString Dirname( const CString &dir )
 CString Capitalize( const CString &s )	
 {
 	if( s.GetLength()==0 )
-		return "";
+		return NULL;
 	CString s2 = s;
 	/* XXX: utf-8 */
 	if( !(s2[0] & 0x80) )