Re: grep.el regexp

[Richard M. Stallman]

    > If that can happen, it is a bug in compile.el.
    > It should never find more than one match on any given line.

    Currently it puts information from different rules on the same line
    when regexps cover different parts of that line (it works this way due
    to the font-lock algorithms).

Do you mean, when different compilation-error regexps match
disjoint parts of the line?

If so, could you show me a case where this happens?
Let's try to prevent it.