Re: setenv -> locale-coding-system cannot handle ASCII?!

[Richard Stallman <rms@gnu.org>]

    > PS: I wish there was a way to swap two buffers's content so that
    >     tar-mode could swap the (potentially very large) data to
    >     a helper buffer (without needing to copy this large data)

    I think tar-mode should use multiple buffers, one unibyte
    buffer for tar-file itself, one multibyte buffer for table
    of contents, and the other multibyte buffers (created on
    demand) for viewing/editing files contained in the tar-file.

It does use other multibyte buffers (created on demand) for
viewing/editing the contained files.  So the change here would
be in using two buffers for the main file.

You would want the buffer that users know about to contain the ASCII
directory listing.  So the buffer that contains the actual tar file
would want to be another file.  That would work fine except perhaps
for complications in reading in the file.  The feature of
swapping contents between two buffers might indeed be useful here.
And it is probably easy to implement.

    Hmm...looking at the code, it does seem like there really isn't
    any save-current-buffer interfering.  Can we rely on that ?
    Should we document it ?
    It's rather unusual for a major-mode function to switch the
    current buffer.

I think that is a kludge, and that contents-swapping for the
same buffer is much cleaner.