gitweb: Modularized git_get_project_description to be more generic

Introduce a git_get_file_or_project_config utility function to
retrieve a repository variable either from a plain text file in the
$GIT_DIR or else from 'gitweb.$variable' in the repository config
(e.g. 'description').

This would be used in next commit to retrieve category for a project,
which is to be stored in the same way as project description.

Signed-off-by: Sebastien Cevey <seb@cine7.net>
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

gitweb/gitweb.perl

@@ -2562,18 +2562,26 @@ sub git_get_path_by_hash {
 ## ......................................................................
 ## git utility functions, directly accessing git repository
 
-sub git_get_project_description {
-	my $path = shift;
+# get the value of config variable either from file named as the variable
+# itself in the repository ($GIT_DIR/$name file), or from gitweb.$name
+# configuration variable in the repository config file.
+sub git_get_file_or_project_config {
+	my ($path, $name) = @_;
 
 	$git_dir = "$projectroot/$path";
-	open my $fd, '<', "$git_dir/description"
-		or return git_get_project_config('description');
-	my $descr = <$fd>;
+	open my $fd, '<', "$git_dir/$name"
+		or return git_get_project_config($name);
+	my $conf = <$fd>;
 	close $fd;
-	if (defined $descr) {
-		chomp $descr;
+	if (defined $conf) {
+		chomp $conf;
 	}
-	return $descr;
+	return $conf;
+}
+
+sub git_get_project_description {
+	my $path = shift;
+	return git_get_file_or_project_config($path, 'description');
 }
 
 # supported formats: