bug#2350: 23.0.90; compilation-mode inserts output in the wrong location

[Stefan Monnier]

> This is arguably not a bug, but the behavior I'd expected is indeed
> useful: sometimes when a compilation is running, I want to study just
> part of the output, and it's convenient to narrow to just the part I
> want.  With the current behavior, though, in order to avoid getting the
> *compilation* buffer's lines all mixed up, I must copy the interesting
> region to another buffer.

This is a fundamental problem in `narrow': its meaning is ambiguous.
Sometimes it is used to pretend that the buffer is really smaller than
it is, and other times it's used just to "focus" on a subpart.
The implementation (i.e. most of the C and Elisp code) tend to take the
first point of view, but sometimes users intend the other.

Maybe a good way to provide what the user wants is to introduce
a notion of window-local narrowing, or a visual-narrowing.


        Stefan