gitweb: href(..., -path_info => 0|1)

If named boolean option -path_info is passed to href() subroutine, it
would use its value to decide whether to generate path_info URL form.
If this option is not passed, href() queries 'pathinfo' feature to
check whether to generate path_info URL (if generating path_info link
is possible at all).

href(-replay=>1, -path_info=>0) is meant to be used to generate a key
for caching gitweb output; alternate solution would be to use freeze()
from Storable (core module) on %input_params hash (or its reference),
e.g.:
  $key = freeze \%input_params;
or other serialization of %input_params.

While at it document extra options/flags to href().

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Acked-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

gitweb/gitweb.perl

@@ -977,6 +977,10 @@ exit;
 ## ======================================================================
 ## action links
 
+# possible values of extra options
+# -full => 0|1      - use absolute/full URL ($my_uri/$my_url as base)
+# -replay => 1      - start from a current view (replay with modifications)
+# -path_info => 0|1 - don't use/use path_info URL (if possible)
 sub href {
 	my %params = @_;
 	# default is to use -absolute url() i.e. $my_uri
@@ -993,7 +997,8 @@ sub href {
 	}
 
 	my $use_pathinfo = gitweb_check_feature('pathinfo');
-	if ($use_pathinfo and defined $params{'project'}) {
+	if (defined $params{'project'} &&
+	    (exists $params{-path_info} ? $params{-path_info} : $use_pathinfo)) {
 		# try to put as many parameters as possible in PATH_INFO:
 		#   - project name
 		#   - action