simplify error check

stepmania/src/CryptHelpers.cpp

@@ -43,7 +43,7 @@ unsigned int RageFileStore::TransferTo2(BufferedTransformation &target, unsigned
 	if (m_waiting)
 		goto output;
 	
-	while( size && m_file.IsGood() )
+	while( size && !m_file.AtEOF() )
 	{
 		{
 			unsigned int spaceSize = 1024;
@@ -51,7 +51,7 @@ unsigned int RageFileStore::TransferTo2(BufferedTransformation &target, unsigned
 			
 			m_len = m_file.Read( (char *)m_space, STDMIN(size, (unsigned long)spaceSize));
 			if( m_len == -1 )
-				throw ReadErr();
+				throw ReadErr( m_file );
 		}
 		unsigned int blockedBytes;
 output:
@@ -63,9 +63,6 @@ output:
 		transferBytes += m_len;
 	}
 	
-	if (!m_file.IsGood() && !m_file.AtEOF())
-		throw ReadErr();
-	
 	return 0;
 }
 

stepmania/src/CryptHelpers.h

@@ -20,7 +20,7 @@ public:
 		Err(const std::string &s) : Exception(IO_ERROR, s) {}
 	};
 	class OpenErr : public Err {public: OpenErr(const std::string &filename) : Err("FileStore: error opening file for reading: " + filename) {}};
-	class ReadErr : public Err {public: ReadErr() : Err("FileStore: error reading file") {}};
+	struct ReadErr : public Err { ReadErr(const RageFile &f) : Err("RageFileStore(" + f.GetPath() + "): read error: " + f.GetError() ) {}};
 
 	RageFileStore() {}
 	RageFileStore(const char *filename)