[PATCH] gitweb: fixes to gitweb feature check code

[Giuseppe Bilotta <giuseppe.bilotta@gmail.com>]

The gitweb_check_feature routine was being used for two different
purposes: retrieving the actual feature value (such as the list of
snapshot formats or the list of additional actions), and to check if a
feature was enabled.

For the latter use, since all features return an array, it led to either
clumsy code or subtle bugs, with disabled features appearing enabled
because (0) evaluates to 1.

We fix these bugs, and simplify the code, by separating feature (list)
value retrieval (gitweb_get_feature) from boolean feature check (i.e.
retrieving the first/only item in the feature value list). Usage of
gitweb_check_feature across gitweb is replaced by the appropriate call
wherever needed.
---
 gitweb/gitweb.perl |   52 +++++++++++++++++++++++++++++++++++-----------------
 1 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 933e137..b0d00ea 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -190,7 +190,9 @@ our %feature = (
 	# if there is no 'sub' key (no feature-sub), then feature cannot be
 	# overriden
 	#
-	# use gitweb_check_feature(<feature>) to check if <feature> is enabled
+	# use gitweb_get_feature(<feature>) to retrieve the <feature> value
+	# (an array) or gitweb_check_feature(<feature>) to check if <feature>
+	# is enabled
 
 	# Enable the 'blame' blob view, showing the last commit that modified
 	# each line in the file. This can be very CPU-intensive.
@@ -329,7 +331,8 @@ our %feature = (
 		'default' => [0]},
 );
 
-sub gitweb_check_feature {
+# retrieve the value of a given feature, as an array
+sub gitweb_get_feature {
 	my ($name) = @_;
 	return unless exists $feature{$name};
 	my ($sub, $override, @defaults) = (
@@ -344,6 +347,21 @@ sub gitweb_check_feature {
 	return $sub->(@defaults);
 }
 
+# check if a given feature is enabled or not, returning the first (and only)
+# value of the feature. Comfort code, allowing the use of
+#   my $bool_feat = gitweb_check_feature('bool_feat');
+# or
+#   gitweb_check_feature('bool_feat') or somecode;
+# instead of
+#   my ($bool_feat) = gitweb_git_feature('bool_feat');
+# or
+#   (gitweb_check_feature('bool_feat'))[0] or somecode;
+# respectively
+sub gitweb_check_feature {
+	return (gitweb_get_feature(@_))[0];
+}
+
+
 sub feature_blame {
 	my ($val) = git_get_project_config('blame', '--bool');
 
@@ -767,7 +785,7 @@ our $git_dir;
 $git_dir = "$projectroot/$project" if $project;
 
 # list of supported snapshot formats
-our @snapshot_fmts = gitweb_check_feature('snapshot');
+our @snapshot_fmts = gitweb_get_feature('snapshot');
 @snapshot_fmts = filter_snapshot_fmts(@snapshot_fmts);
 
 # dispatch
@@ -810,7 +828,7 @@ sub href (%) {
 		}
 	}
 
-	my ($use_pathinfo) = gitweb_check_feature('pathinfo');
+	my $use_pathinfo = gitweb_check_feature('pathinfo');
 	if ($use_pathinfo) {
 		# try to put as many parameters as possible in PATH_INFO:
 		#   - project name
@@ -2101,7 +2119,7 @@ sub git_get_projects_list {
 	$filter ||= '';
 	$filter =~ s/\.git$//;
 
-	my ($check_forks) = gitweb_check_feature('forks');
+	my $check_forks = gitweb_check_feature('forks');
 
 	if (-d $projects_list) {
 		# search in directory
@@ -2947,7 +2965,7 @@ EOF
 	}
 	print "</div>\n";
 
-	my ($have_search) = gitweb_check_feature('search');
+	my $have_search = gitweb_check_feature('search');
 	if (defined $project && $have_search) {
 		if (!defined $searchtext) {
 			$searchtext = "";
@@ -2961,7 +2979,7 @@ EOF
 			$search_hash = "HEAD";
 		}
 		my $action = $my_uri;
-		my ($use_pathinfo) = gitweb_check_feature('pathinfo');
+		my $use_pathinfo = gitweb_check_feature('pathinfo');
 		if ($use_pathinfo) {
 			$action .= "/".esc_url($project);
 		}
@@ -3084,7 +3102,7 @@ sub git_print_page_nav {
 	$arg{'tree'}{'hash'} = $treehead if defined $treehead;
 	$arg{'tree'}{'hash_base'} = $treebase if defined $treebase;
 
-	my @actions = gitweb_check_feature('actions');
+	my @actions = gitweb_get_feature('actions');
 	my %repl = (
 		'%' => '%',
 		'n' => $project,         # project name
@@ -3454,7 +3472,7 @@ sub is_patch_split {
 sub git_difftree_body {
 	my ($difftree, $hash, @parents) = @_;
 	my ($parent) = $parents[0];
-	my ($have_blame) = gitweb_check_feature('blame');
+	my $have_blame = gitweb_check_feature('blame');
 	print "<div class=\"list_head\">\n";
 	if ($#{$difftree} > 10) {
 		print(($#{$difftree} + 1) . " files changed:\n");
@@ -3968,7 +3986,7 @@ sub git_project_list_body {
 	# actually uses global variable $project
 	my ($projlist, $order, $from, $to, $extra, $no_header) = @_;
 
-	my ($check_forks) = gitweb_check_feature('forks');
+	my $check_forks = gitweb_check_feature('forks');
 	my @projects = fill_project_list_info($projlist, $check_forks);
 
 	$order ||= $default_projects_order;
@@ -4428,7 +4446,7 @@ sub git_summary {
 	my @taglist  = git_get_tags_list(16);
 	my @headlist = git_get_heads_list(16);
 	my @forklist;
-	my ($check_forks) = gitweb_check_feature('forks');
+	my $check_forks = gitweb_check_feature('forks');
 
 	if ($check_forks) {
 		@forklist = git_get_projects_list($project);
@@ -4457,7 +4475,7 @@ sub git_summary {
 	}
 
 	# Tag cloud
-	my $show_ctags = (gitweb_check_feature('ctags'))[0];
+	my $show_ctags = gitweb_check_feature('ctags');
 	if ($show_ctags) {
 		my $ctags = git_get_project_ctags($project);
 		my $cloud = git_populate_project_tagcloud($ctags);
@@ -4747,7 +4765,7 @@ sub git_blob {
 		$expires = "+1d";
 	}
 
-	my ($have_blame) = gitweb_check_feature('blame');
+	my $have_blame = gitweb_check_feature('blame');
 	open my $fd, "-|", git_cmd(), "cat-file", "blob", $hash
 		or die_error(500, "Couldn't cat $file_name, $hash");
 	my $mimetype = blob_mimetype($fd, $file_name);
@@ -4840,7 +4858,7 @@ sub git_tree {
 	my $ref = format_ref_marker($refs, $hash_base);
 	git_header_html();
 	my $basedir = '';
-	my ($have_blame) = gitweb_check_feature('blame');
+	my $have_blame = gitweb_check_feature('blame');
 	if (defined $hash_base && (my %co = parse_commit($hash_base))) {
 		my @views_nav = ();
 		if (defined $file_name) {
@@ -5838,7 +5856,7 @@ insensitive).</p>
 <dt><b>commit</b></dt>
 <dd>The commit messages and authorship information will be scanned for the given pattern.</dd>
 EOT
-	my ($have_grep) = gitweb_check_feature('grep');
+	my $have_grep = gitweb_check_feature('grep');
 	if ($have_grep) {
 		print <<EOT;
 <dt><b>grep</b></dt>
@@ -5855,7 +5873,7 @@ EOT
 <dt><b>committer</b></dt>
 <dd>Name and e-mail of the committer and date of commit will be scanned for the given pattern.</dd>
 EOT
-	my ($have_pickaxe) = gitweb_check_feature('pickaxe');
+	my $have_pickaxe = gitweb_check_feature('pickaxe');
 	if ($have_pickaxe) {
 		print <<EOT;
 <dt><b>pickaxe</b></dt>
@@ -5907,7 +5925,7 @@ sub git_shortlog {
 
 sub git_feed {
 	my $format = shift || 'atom';
-	my ($have_blame) = gitweb_check_feature('blame');
+	my $have_blame = gitweb_check_feature('blame');
 
 	# Atom: http://www.atomenabled.org/developers/syndication/
 	# RSS:  http://www.notestips.com/80256B3A007F2692/1/NAMO5P9UPQ
-- 
1.5.6.5