gitweb: Allow UTF-8 encoded CGI query parameters and path_info

Gitweb forgot to turn query parameters into UTF-8. This results in a bug that one cannot search for a string with 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%82) result in the following incorrect data in search field MichaÅ\202 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); Decoding UTF-8 is done when filling %input_params hash and $path_info variable; the former requires to move from explicit $cgi->param(<label>) to $input_params{<name>} in a few places, which is a good idea anyway. Also add -override=>1 parameter to $cgi->textfield() invocation in search form. Otherwise CGI would use values from query string if it is present, filling value from $cgi->param... without decode_utf8(). As we are using value of appropriate parameter anyway, -override=>1 doesn't change the situation but makes gitweb fill search field correctly. We could simply use the '-utf8' pragma (via "use CGI '-utf8';") to solve this, but according to CGI.pm documentation, it may cause problems with POST requests containing binary files, and it requires CGI 3.31 (I think), released with perl v5.8.9. Reported-by: Michał Kiedrowicz <michal.kiedrowicz@gmail.com> Signed-off-by: Jakub Narębski <jnareb@gmail.com> Tested-by: Michał Kiedrowicz <michal.kiedrowicz@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>