Re: [Gnu-arch-users] tagline robustness

[Tom Lord]

    > From: Miles Bader <address@hidden>

    > For instance, all the following taglines refer to _different_ tags:

    >    /* arch-tag: my-gnarly-tag <address@hidden>
    >     */

    >    /* arch-tag: my-gnarly-tag  <address@hidden>
    >     */

    >    /* arch-tag: my-gnarly-tag <address@hidden> */

    >    /* arch-tag: my-gnarly-tag <address@hidden>  */

    > even though to a casual user, they look basically equivalent.

Ok, I can see that that's an annoyance.

    > I suggest that should go much further than it does now in reducing
    > taglines to a canonical form:  instead of just removing preceding and
    > trailing whitespace, _ignore_ any characters not in a restricted subset.
    > A good subset might be:  address@hidden

    > This can be accomplished in a backward-compatible way in two easy steps:

    >   (1) Change the way arch compares tags to ignore non-subset characters
    >       in comparisons (and any hash-table indexing or whatever), but keep
    >       _producing_ tags (e.g. what's written to mod-files-index and
    >       orig-files-index) using the old rules.

    >       Change the documentation to say `only these characters are
    >       significant ...'.

    >       This way people with old versions of tla/arch/whatever will
    >       continue to see the same archive contents, and as long as people
    >       are careful with their taglines (as they've _had_ to be until now,
    >       so there's not reason for them to change), there's no effect.

    >       I think it's _extremely_ unlikely that anyone has made taglines
    >       such that the above change would produce any conflicts.

I agree that it's unlikely.   Nevertheless, the change you've
described is not strictly upwards compatible   I don't like the idea
for that reason.

-t