it's someone else's code crashing and Winamp cannot recover from that (i.e. it's just the same as the old Gracenote issues).
in_flac.dll - Winamp plug-in
libflac.dll / libflac library- xiph provided library which in_flac.dll uses for all of the decoding of the flac files.
it's the libflac part i.e. the external / 3rd party library where the crash happens and since it crashes in that, there's little that Winamp / in_flac.dll can really do to handle a crash which is effectively outside of our control.
since the libflac source code is available, a possible patch could be provided, but without further research and time, for all i know it's already been fixed already with the updates made since libflac v1.3.0 was released (as per the changes shown in https://git.xiph.org/?p=flac.git;a=shortlog
). or it will still require debugging and making a custom patch.
at times i really regret trying to explain things further as really it shouldn't matter as whatever a 3rd party library does or doesn't do, it's Winamp that gets the blame for the crash and trying to dumb down what's actually going on is just more confusing in the long run (especially for a non-coded like yourself).