Re: [PATCH/RFC (version A)] gitweb: use CGI with -utf8 to process Unicode query parameters correctly

> Gitweb tries hard to properly process UTF-8 data, by marking output
> from git commands and contents of files as UTF-8 with to_utf8()
> subroutine.  This ensures that gitweb would print correctly UTF-8
> e.g. in 'log' and 'commit' views.
> 
> Unfortunately it misses another source of potentially Unicode input,
> namely query parameters.  The result is that one cannot search for a
> string containing characters outside US-ASCII.  For example searching
> for "Michał Kiedrowicz" (containing letter 'ł' - LATIN SMALL LETTER L
> WITH STROKE, with Unicode codepoint U+0142, represented with 0xc5 0x82
> bytes in UTF-8 and percent-encoded as %C5%81) result in the following
> incorrect data in search field
> 
> 	Michał Kiedrowicz
> 
> This is caused by CGI by default treating '0xc5 0x82' bytes as two
> characters in Perl legacy encoding latin-1 (iso-8859-1), because 's'
> query parameter is not processed explicitly as UTF-8 encoded string.
> 
> According to "Using Unicode in a Perl CGI script" article on
> http://www.lemoda.net/cgi/perl-unicode/index.html the simplest
> solution is to just import '-utf8' pragma for CGI module:
> 
> 	use CGI '-utf8';
> 	my $value = params('input');
> 
> According to CGI module documentation, the '-utf8' pragma may cause
> problems with POST requests containing binary files... but gitweb
> currently do not use POST requests at all, so this should be not a
> problem now.

> 
> Alternate solution would be to explicity decode query parameters when
> storing them in %input_params (and perhaps also path_info).
> 
> [jn: reworded / rewritten commit message]
> 
> Signed-off-by: Michał Kiedrowicz <michal.kiedrowicz@gmail.com>

> Signed-off-by: Jakub Narębski <jnareb@gmail.com>
> ---
>  gitweb/gitweb.perl |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
> index 9cf7e71..a7441ef 100755
> --- a/gitweb/gitweb.perl
> +++ b/gitweb/gitweb.perl
> @@ -10,7 +10,7 @@
>  use 5.008;
>  use strict;
>  use warnings;
> -use CGI qw(:standard :escapeHTML -nosticky);
> +use CGI qw(:standard :escapeHTML -nosticky -utf8);
>  use CGI::Util qw(unescape);
>  use CGI::Carp qw(fatalsToBrowser set_message);
>  use Encode;