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openMSX / openMSX

the MSX emulator that aims for perfection
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[Bug] Read/write media are opened RW, which can break replay [sf#401] #795

Open openMSX-import opened 9 years ago

openMSX-import commented 9 years ago

Reported by manuelbi on 2010-08-15 21:13 UTC Currently, openMSX opens read/write media RW, even when recording and replaying event logs. This will make it possible to break even random files on your system if someone gives you a prepared replay file to replay. But, it will also break replays in certain cases, because the written data cannot be undone and the state of the media will hence not be the same each time.(There is no known case for this though.) At the moment, openMSX does check if the file ahs been modified and then generates a warning and opens the file read only after all. This covers most security cases and luckily we have no known games that rely on modification of media. But for debugging purposes etc., it may still be a pain.

Ilari on IRC uses a Copy On Write system for his emulator to address this issue. We should implement this in openMSX some time as well.

openMSX-import commented 9 years ago

Updated by manuelbi on 2010-08-15 21:14 UTC