fixed crashes when ini, log, and cache files are read-only

stepmania/src/IniFile.cpp

@@ -92,6 +92,10 @@ bool IniFile::ReadFile()
 void IniFile::WriteFile()
 {
 	FILE* fp = fopen( path, "w" );
+
+	if( fp == NULL )
+		return;
+
 	for (keymap::const_iterator k = keys.begin(); k != keys.end(); ++k)
 	{
 		if (k->second.empty())

stepmania/src/NotesWriterSM.cpp

@@ -3,6 +3,7 @@
 #include "Notes.h"
 #include "RageUtil.h"
 #include "GameManager.h"
+#include "RageLog.h"
 
 void NotesWriterSM::WriteGlobalTags(FILE *fp, const Song &out)
 {
@@ -95,7 +96,10 @@ bool NotesWriterSM::Write(CString sPath, const Song &out, bool bSavingCache)
 
 	FILE* fp = fopen( sPath, "w" );	
 	if( fp == NULL )
-		RageException::Throw( "Error opening song file '%s' for writing.", sPath.GetString() );
+	{
+		LOG->Warn( "Error opening song file '%s' for writing.", sPath.GetString() );
+		return false;
+	}
 
 	WriteGlobalTags(fp, out);
 	if(bSavingCache) {

stepmania/src/RageLog.cpp

@@ -45,7 +45,8 @@ RageLog::~RageLog()
 {
 	Flush();
 	FreeConsole();
-	fclose( m_fileLog );
+	if( m_fileLog )
+		fclose( m_fileLog );
 }
 
 void RageLog::ShowConsole()
@@ -68,7 +69,8 @@ void RageLog::Trace( const char *fmt, ...)
     CString sBuff = vssprintf( fmt, va );
     va_end(va);
 
-	fprintf( m_fileLog, "%s\n", sBuff.GetString() ); 
+	if( m_fileLog )
+		fprintf( m_fileLog, "%s\n", sBuff.GetString() ); 
 	printf( "%s\n", sBuff.GetString() ); 
 	CrashLog(sBuff);