[Gnu-arch-users] Binary diffs (Re: Some issues)

[Lőrentey Károly]

Thomas Bleher <address@hidden> writes:
> * Matthieu Moy <address@hidden> [2004-06-09 18:24]:
>> Andrew Suffield <address@hidden> writes:
>> 
>> > That has got more or less nothing to do with the changeset format;
>> > it's an optimisation that can, should, and likely will be done
>> > externally to tla and without changing anything about the changesets.
>> 
>> Where would you  put this optimization, if not in  tla? (That's a real
>> question, I don't understand what you mean)
>
> This has been discussed on the mailing list before. See the thread
> starting at [0] especially the message from Tom[1] where he discusses
> the steps that need to be taken to effectively support binary diffs.
> Essentially you only have to patch diff, patch and diff3, tla is
> practically unaffected by this change.

I don't think a GNU Diffutils+Patch version 3.0 with support for
binary files will magically appear from thin air tomorrow.[*] With
some very careful work, I expect one could indeed put together some
wrappers to get diff & friends to DTRT.  But if everyone who needs
binary diffs would need to perform a gut transplant on tla by using a
low-level third-party "backend wrapper" (note cool term), we would end
up with a multitude of incompatible changeset formats and would kiss
goodbye to archive interoperability.  Or am I missing something
obvious here?

By the way, is it possible to set archive-dependent paths for diff & co.?

With all due respect, I think Florian had a good point here.
Space-efficient binary file support is a feature that AFAICS tla does
*not* support at the moment (while both Subversion and Bitkeeper do).
Considering that noone (again, AFAICS) is actually working on it, it
is likely to stay this way for a while.  Those who find that feature
critically important should expect to be disappointed, unless they
have the time to implement it themselves, or the money to hire someone
to implement it for them.  No?

Not that I think this is such a big issue (CVS--God rest its soul--had
no binary diff support, and that had never been a real problem for
me), but I think it's unfair to dismiss it like that. "You only have
to patch diff, patch and diff3", indeed.

[*] If the vague rumours about binary file support under development
    for diff/patch turn out to be true, then please disregard this
    message. :-) I could not find either a public CVS mirror or a
    public mailing list to verify this.  Diffutils is actively
    maintained, but the latest alpha version (2.8.7) at
    ftp://alpha.gnu.org/gnu/diffutils/ has no extra support for binary
    files, and has no indication of any new and exciting features
    secretly brewing at Diffutils Headquarters.  I am sceptical.

-- 
Károly
First poster, set me on fire! :-)