might help with portability, see for e.g. GitHub issue #1

we're just gonna memcpy all over path again a couple of lines before; a smart compiler will probably ignore the initialization anyway.

was the only function to disrespect the player_* namespace (well, excepting play). while here also don't mark those two as static, they were the only static functions in the file. I'm not trying to enforcing private symbols here.

we don't know what format the music will be so we have to stop and set the parameters in player_setup. there's no point in setting bogus parameter in audio_init.

don't need to keep `files' around, res->files is enough. it would have prevented the previous bug (probably.)

don't advance the files pointer, we need the original pointer when receiving the replies.

the approach with one-function-per-imsg leads to too much code splatted across the file.

player_dispatch reads only one imsg from the ibuf. Next time it's called, the other messages on the ibuf (if any) are discarded and new ones are read. This can cause the player process to go out-of-sync with the main process if multiple messages were "bundled" in the same chunk. To avoid this, always try to imsg_read before. If it succeedes, we read process the equeued messages one by one, if it fails then we poll for new data and call imsg_read to process them and retry. This fixes a bug where amused could be "confused" by running $ amused pause ; amused stop ; amused play in a loop a few times. This bug and the repro were reported two months ago by Dirk-Wilhelm Peters, thanks! (and sorry it took so long to understand and fix the issue)