Subject: Re: [PATCH/RFC (version B)] gitweb: Allow UTF-8 encoded CGI query parameters and path_info

From: Michał Kiedrowicz <[email-masked]>
Date: Thu, 2 Feb 2012 21:46:46 +0100

Jakub Narebski <[email-masked]> wrote:

> 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
> 
> 	MichaÅ 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.
> 
> The solution used here follows "Using Unicode in a Perl CGI script"
> article on http://www.lemoda.net/cgi/perl-unicode/index.html:
> 
> 	use CGI;
> 	use Encode 'decode_utf8;
> 	my $value = params('input');
> 	$value = decode_utf8($value);
> 
> This is done when filling %input_params hash; this required to move
> from explicit $cgi->param(<label>) to $input_params{<name>} in a few
> places.

I'm sorry but this doesn't work for me. I would be happy to help if you
have some questions about it.

> 
> Alternate solution would be to simply use the '-utf8' pragma (via
> "use CGI '-utf8';"), but according to CGI.pm documentation it may
> cause problems with POST requests containing binary files... and
> it doesn't work with old CGI.pm version 3.10 from Perl v5.8.6.
> 
> Noticed-by: Michał Kiedrowicz <[email-masked]>
> Signed-off-by: Jakub Narębski <[email-masked]>
> ---
>  gitweb/gitweb.perl |   12 ++++++------
>  1 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
> index 9cf7e71..55b2c24 100755
> --- a/gitweb/gitweb.perl
> +++ b/gitweb/gitweb.perl
> @@ -52,7 +52,7 @@ sub evaluate_uri {
>  	# as base URL.
>  	# Therefore, if we needed to strip PATH_INFO, then we know that we have
>  	# to build the base URL ourselves:
> -	our $path_info = $ENV{"PATH_INFO"};
> +	our $path_info = decode_utf8($ENV{"PATH_INFO"});
>  	if ($path_info) {
>  		if ($my_url =~ s,\Q$path_info\E$,, &&
>  		    $my_uri =~ s,\Q$path_info\E$,, &&
> @@ -816,9 +816,9 @@ sub evaluate_query_params {
>  
>  	while (my ($name, $symbol) = each %cgi_param_mapping) {
>  		if ($symbol eq 'opt') {
> -			$input_params{$name} = [ $cgi->param($symbol) ];
> +			$input_params{$name} = [ map { decode_utf8($_) } $cgi->param($symbol) ];
>  		} else {
> -			$input_params{$name} = $cgi->param($symbol);
> +			$input_params{$name} = decode_utf8($cgi->param($symbol));
>  		}
>  	}
>  }
> @@ -2767,7 +2767,7 @@ sub git_populate_project_tagcloud {
>  	}
>  
>  	my $cloud;
> -	my $matched = $cgi->param('by_tag');
> +	my $matched = $input_params{'ctag'};
>  	if (eval { require HTML::TagCloud; 1; }) {
>  		$cloud = HTML::TagCloud->new;
>  		foreach my $ctag (sort keys %ctags_lc) {
> @@ -5282,7 +5282,7 @@ sub git_project_list_body {
>  
>  	my $check_forks = gitweb_check_feature('forks');
>  	my $show_ctags  = gitweb_check_feature('ctags');
> -	my $tagfilter = $show_ctags ? $cgi->param('by_tag') : undef;
> +	my $tagfilter = $show_ctags ? $input_params{'ctag'} : undef;
>  	$check_forks = undef
>  		if ($tagfilter || $searchtext);
>  
> @@ -6197,7 +6197,7 @@ sub git_tag {
>  
>  sub git_blame_common {
>  	my $format = shift || 'porcelain';
> -	if ($format eq 'porcelain' && $cgi->param('js')) {
> +	if ($format eq 'porcelain' && $input_params{'javascript'}) {
>  		$format = 'incremental';
>  		$action = 'blame_incremental'; # for page title etc
>  	}