Re: Several serious problems

[Richard Stallman]

    Do you mean a command something like this?

    (defun check-coding-system-region (from to coding-system &optional max-num)
      "Check if the text after point is encodable by the specified coding 
system.
    When called from a program, takes three arguments:
    CODING-SYSTEM, FROM, and TO.  START and END are buffer positions.
    Value is a list of positions of characters that are not encodable by
    CODING-SYSTEM.
    Optional 4th argument MAX-NUM, if non-nil, limits the length of
    returned list.  By default, there's no limit."

This could do the internals of the job.  To be useful, it needs a user
interface.

How about if you modify it to make overlays to highlight those characters
instead of returning a list saying where they are?