gitweb: Document features better

This expands gitweb/README to talk some more about GITWEB_CONFIG, moves
feature-specific documentation in gitweb.cgi to the inside of the %features
array, and adds some short description of all the features.

Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>

gitweb/README

@@ -24,11 +24,25 @@ You can specify the following configuration variables when building GIT:
  * GITWEB_LOGO
    Points to the location where you put git-logo.png on your web server.
  * GITWEB_CONFIG
-   This file will be loaded using 'require'.  If the environment
+   This file will be loaded using 'require' and can be used to override any
+   of the options above as well as some other options - see the top of
+   'gitweb.cgi' for their full list and description.  If the environment
    $GITWEB_CONFIG is set when gitweb.cgi is executed the file in the
    environment variable will be loaded instead of the file
    specified when gitweb.cgi was created.
 
+Runtime gitweb configuration
+----------------------------
+
+You can adjust gitweb behaviour using the file specified in `GITWEB_CONFIG`
+(defaults to 'gitweb_config.perl' in the same directory as the CGI).
+See the top of 'gitweb.cgi' for the list of variables and some description.
+The most notable thing that is not configurable at compile time are the
+optional features, stored in the '%features' variable. You can find further
+description on how to reconfigure the default features setting in your
+`GITWEB_CONFIG` or per-project in `project.git/config` inside 'gitweb.cgi'.
+
+
 Originally written by:
   Kay Sievers <kay.sievers@vrfy.org>
 

gitweb/gitweb.perl

@@ -87,22 +87,63 @@
 	#
 	# use 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.
+
+	# To enable system wide have in $GITWEB_CONFIG
+	# $feature{'blame'}{'default'} = [1];
+	# To have project specific config enable override in $GITWEB_CONFIG
+	# $feature{'blame'}{'override'} = 1;
+	# and in project config gitweb.blame = 0|1;
 	'blame' => {
 		'sub' => \&feature_blame,
 		'override' => 0,
 		'default' => [0]},
 
+	# Enable the 'snapshot' link, providing a compressed tarball of any
+	# tree. This can potentially generate high traffic if you have large
+	# project.
+
+	# To disable system wide have in $GITWEB_CONFIG
+	# $feature{'snapshot'}{'default'} = [undef];
+	# To have project specific config enable override in $GITWEB_CONFIG
+	# $feature{'blame'}{'override'} = 1;
+	# and in project config gitweb.snapshot = none|gzip|bzip2;
 	'snapshot' => {
 		'sub' => \&feature_snapshot,
 		'override' => 0,
 		#         => [content-encoding, suffix, program]
 		'default' => ['x-gzip', 'gz', 'gzip']},
 
+	# Enable the pickaxe search, which will list the commits that modified
+	# a given string in a file. This can be practical and quite faster
+	# alternative to 'blame', but still potentially CPU-intensive.
+
+	# To enable system wide have in $GITWEB_CONFIG
+	# $feature{'pickaxe'}{'default'} = [1];
+	# To have project specific config enable override in $GITWEB_CONFIG
+	# $feature{'pickaxe'}{'override'} = 1;
+	# and in project config gitweb.pickaxe = 0|1;
 	'pickaxe' => {
 		'sub' => \&feature_pickaxe,
 		'override' => 0,
 		'default' => [1]},
 
+	# Make gitweb use an alternative format of the URLs which can be
+	# more readable and natural-looking: project name is embedded
+	# directly in the path and the query string contains other
+	# auxiliary information. All gitweb installations recognize
+	# URL in either format; this configures in which formats gitweb
+	# generates links.
+
+	# To enable system wide have in $GITWEB_CONFIG
+	# $feature{'pathinfo'}{'default'} = [1];
+	# Project specific override is not supported.
+
+	# Note that you will need to change the default location of CSS,
+	# favicon, logo and possibly other files to an absolute URL. Also,
+	# if gitweb.cgi serves as your indexfile, you will need to force
+	# $my_uri to contain the script name in your $GITWEB_CONFIG.
 	'pathinfo' => {
 		'override' => 0,
 		'default' => [0]},
@@ -123,12 +164,6 @@ sub gitweb_check_feature {
 	return $sub->(@defaults);
 }
 
-# To enable system wide have in $GITWEB_CONFIG
-# $feature{'blame'}{'default'} = [1];
-# To have project specific config enable override in $GITWEB_CONFIG
-# $feature{'blame'}{'override'} = 1;
-# and in project config gitweb.blame = 0|1;
-
 sub feature_blame {
 	my ($val) = git_get_project_config('blame', '--bool');
 
@@ -141,12 +176,6 @@ sub feature_blame {
 	return $_[0];
 }
 
-# To disable system wide have in $GITWEB_CONFIG
-# $feature{'snapshot'}{'default'} = [undef];
-# To have project specific config enable override in $GITWEB_CONFIG
-# $feature{'blame'}{'override'} = 1;
-# and in project config  gitweb.snapshot = none|gzip|bzip2
-
 sub feature_snapshot {
 	my ($ctype, $suffix, $command) = @_;
 
@@ -170,12 +199,6 @@ sub gitweb_have_snapshot {
 	return $have_snapshot;
 }
 
-# To enable system wide have in $GITWEB_CONFIG
-# $feature{'pickaxe'}{'default'} = [1];
-# To have project specific config enable override in $GITWEB_CONFIG
-# $feature{'pickaxe'}{'override'} = 1;
-# and in project config gitweb.pickaxe = 0|1;
-
 sub feature_pickaxe {
 	my ($val) = git_get_project_config('pickaxe', '--bool');