Coding System Fun

I have a little question for you. What is the difference in Emacs between the undecided coding system when passed to decode-coding-string or set using set-process-coding-system? None? Tough luck.

When the coding system on a process is undecided, the process will remember and continue to use the coding system it first decides on to use. The solution for my application was to repeat set-process-coding-system on each invocation of the process filter, as to enforce a new decision on each incoming string.