RE: with-output-to-temp-buffer and help-mode

[Stephen J. Turnbull]

Drew Adams writes:

 > No.  Please read what I wrote.

tl;dr

Your point is actually rather subtle (though the general outline is
well-known), and some important ideas were left implicit.  I don't
really quarrel with the notion that long-timers on this list probably
should "get" it without it being made explicit, but if not, don't put
the burden on the reader.  Not everybody is a long-time reader, and
not all of the long-timers will necessarily have their heads in the
right place.

Rather than argue who said what, point by point, here's the argument
in much more explicit form.

1.  The "traditional" implementation of `with-output-to-temp-buffer'
    provides (by default, and without option) many features to support
    help-mode.  (Fact: nobody argues with this.)
2.  Use cases where those features are important are in fact common,
    both in Emacs and in third-party code.
3.  The argument does not depend at all on the existence or frequency
    of use cases that don't use the help features.  Where they
    actually get in the way, it's probably rarely visible to the user
    as existing code has *already* worked around those issues.
4.  Because of (2), backward-compatibility demands that the
    traditional name continue to have these traditional semantics --
    any change causes widespread breakage, not all of which is
    possible to fix.  (Leo seems to be ignoring this.)
5.  The strategy to deal with this (provide a new alias indicating the
    traditional semantics properly, and a new function with an
    appropriate name to indicate the non-help semantics) is
    well-known, is well-known to have worked well in similar
    circumstances, and should be adopted here, too.
    We even know *why* it works well: because of (3), only new code
    has need for the new function, and in new code it's almost as easy
    to use a function with a new name as the documentation for the
    "obvious" name will indicate that it's a backward compatibility
    kludge.
6.  Accept that the "best" name for the new function is unavailable,
    and move on.  (This seems to be hard for many developers to do,
    not just in Emacs. ;-)
7.  Implementation strategy (duplicate the simple logic for a non-help
    buffer, reimplement `with-output-to-temp-buffer' using the new
    function, something else) is up to the implementer.  (Of course.)

It's true that you've written almost all of that, almost all in
equivalent words, but it's spread over many more lines and several
posts.