+
+# input parameters can be collected from a variety of sources (presently, CGI
+# and PATH_INFO), so we define an %input_params hash that collects them all
+# together during validation: this allows subsequent uses (e.g. href()) to be
+# agnostic of the parameter origin
+
+my %input_params = ();
+
+# input parameters are stored with the long parameter name as key. This will
+# also be used in the href subroutine to convert parameters to their CGI
+# equivalent, and since the href() usage is the most frequent one, we store
+# the name -> CGI key mapping here, instead of the reverse.
+#
+# XXX: Warning: If you touch this, check the search form for updating,
+# too.
+
+my @cgi_param_mapping = (
+ project => "p",
+ action => "a",
+ file_name => "f",
+ file_parent => "fp",
+ hash => "h",
+ hash_parent => "hp",
+ hash_base => "hb",
+ hash_parent_base => "hpb",
+ page => "pg",
+ order => "o",
+ searchtext => "s",
+ searchtype => "st",
+ snapshot_format => "sf",
+ extra_options => "opt",
+ search_use_regexp => "sr",
+);
+my %cgi_param_mapping = @cgi_param_mapping;
+
+# we will also need to know the possible actions, for validation
+my %actions = (
+ "blame" => \&git_blame,
+ "blobdiff" => \&git_blobdiff,
+ "blobdiff_plain" => \&git_blobdiff_plain,
+ "blob" => \&git_blob,
+ "blob_plain" => \&git_blob_plain,
+ "commitdiff" => \&git_commitdiff,
+ "commitdiff_plain" => \&git_commitdiff_plain,
+ "commit" => \&git_commit,
+ "forks" => \&git_forks,
+ "heads" => \&git_heads,
+ "history" => \&git_history,
+ "log" => \&git_log,
+ "rss" => \&git_rss,
+ "atom" => \&git_atom,
+ "search" => \&git_search,
+ "search_help" => \&git_search_help,
+ "shortlog" => \&git_shortlog,
+ "summary" => \&git_summary,
+ "tag" => \&git_tag,
+ "tags" => \&git_tags,
+ "tree" => \&git_tree,
+ "snapshot" => \&git_snapshot,
+ "object" => \&git_object,
+ # those below don't need $project
+ "opml" => \&git_opml,
+ "project_list" => \&git_project_list,
+ "project_index" => \&git_project_index,
+);
+
+# finally, we have the hash of allowed extra_options for the commands that
+# allow them
+my %allowed_options = (
+ "--no-merges" => [ qw(rss atom log shortlog history) ],
+);
+
+# fill %input_params with the CGI parameters. All values except for 'opt'
+# should be single values, but opt can be an array. We should probably
+# build an array of parameters that can be multi-valued, but since for the time
+# being it's only this one, we just single it out
+while (my ($name, $symbol) = each %cgi_param_mapping) {
+ if ($symbol eq 'opt') {
+ $input_params{$name} = [ $cgi->param($symbol) ];
+ } else {
+ $input_params{$name} = $cgi->param($symbol);
+ }
+}
+
+# now read PATH_INFO and update the parameter list for missing parameters
+sub evaluate_path_info {
+ return if defined $input_params{'project'};
+ return if !$path_info;
+ $path_info =~ s,^/+,,;
+ return if !$path_info;
+
+ # find which part of PATH_INFO is project
+ my $project = $path_info;
+ $project =~ s,/+$,,;
+ while ($project && !check_head_link("$projectroot/$project")) {
+ $project =~ s,/*[^/]*$,,;
+ }
+ return unless $project;
+ $input_params{'project'} = $project;
+
+ # do not change any parameters if an action is given using the query string
+ return if $input_params{'action'};
+ $path_info =~ s,^\Q$project\E/*,,;
+
+ my ($refname, $pathname) = split(/:/, $path_info, 2);
+ if (defined $pathname) {
+ # we got "project.git/branch:filename" or "project.git/branch:dir/"
+ # we could use git_get_type(branch:pathname), but it needs $git_dir
+ $pathname =~ s,^/+,,;
+ if (!$pathname || substr($pathname, -1) eq "/") {
+ $input_params{'action'} = "tree";
+ $pathname =~ s,/$,,;
+ } else {
+ $input_params{'action'} = "blob_plain";
+ }
+ $input_params{'hash_base'} ||= $refname;
+ $input_params{'file_name'} ||= $pathname;
+ } elsif (defined $refname) {
+ # we got "project.git/branch"
+ $input_params{'action'} = "shortlog";
+ $input_params{'hash'} ||= $refname;
+ }
+}
+evaluate_path_info();
+
+our $action = $input_params{'action'};