Re: [PATCH] cvsserver: change generation of CVS author names

[Junio C Hamano <gitster@pobox.com>]

Fabian Emmes <fabian.emmes@rwth-aachen.de> writes:

> CVS username is generated from local part email address.
> We take the whole local part but restrict the character set to the
> Portable Filename Character Set, which is used for Unix login names
> according to Single Unix Specification v3.
>
> Signed-off-by: Fabian Emmes <fabian.emmes@rwth-aachen.de>
> Signed-off-by: Lars Noschinski <lars@public.noschinski.de>

Stating "we should have done this from day one" is one thing (even though
"because some standard says so" is not particularly a good justification
without "and matches the way people use CVS in the real world in practice"
appended to it).

"We should suddenly change the behaviour" is quite a different thing and
it depends on what follows that sentence if the change is justifiable.  We
do not want to hear "...; screw the existing repositories if they have
nonconforming names.".  It is Ok if it is "...; existing repositories will
be affected, but the damage is limited to very minor set of operations,
namely X, Y and Z".

In other words, is there any backward compatibility issue when a
repository that has served existing CVS users and checkouts with older
version switches to the patched one?  If there is one, is that grave
enough that we should care?

>  git-cvsserver.perl |   12 +++++++++---
>  1 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/git-cvsserver.perl b/git-cvsserver.perl
> index cbcaeb4..fef7faf 100755
> --- a/git-cvsserver.perl
> +++ b/git-cvsserver.perl
> @@ -2533,12 +2533,18 @@ sub open_blob_or_die
>      return $fh;
>  }
>  
> -# Generate a CVS author name from Git author information, by taking
> -# the first eight characters of the user part of the email address.
> +# Generate a CVS author name from Git author information, by taking the local
> +# part of the email address and replacing characters not in the Portable
> +# Filename Character Set (see IEEE Std 1003.1-2001, 3.276) by underscores. CVS
> +# Login names are Unix login names, which should be restricted to this
> +# character set.
>  sub cvs_author
>  {
>      my $author_line = shift;
> -    (my $author) = $author_line =~ /<([^>@]{1,8})/;
> +    (my $author) = $author_line =~ /<([^@>]*)/;
> +
> +    $author =~ s/[^-a-zA-Z0-9_.]/_/g;
> +    $author =~ s/^-/_/;
>  
>      $author;
>  }