[PATCH/RFR&A] gitweb: Better processing format string in custom links in navbar

[Junio C Hamano <gitster@pobox.com>]

I was not around when this was posted and discussed; Shawn's note says
this is waiting for "some sort of response from Pasky", hence this request
for review and ack.  It still is parked in 'pu'.

-- >8 --

Make processing format string in custom links in action bar ('actions'
feature) more robust.  Now there would be no problems if one of
expanded values (for example project name, of project filename)
contains '%'; additionally format string supports '%' escaping by
doubling, i.e. '%%' expands to '%'.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 gitweb/gitweb.perl |   19 ++++++++++++-------
 1 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 1116800..cc6edbe 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -290,10 +290,10 @@ our %feature = (
 
 	# The 'default' value consists of a list of triplets in the form
 	# (label, link, position) where position is the label after which
-	# to inster the link and link is a format string where %n expands
+	# to insert the link and link is a format string where %n expands
 	# to the project name, %f to the project path within the filesystem,
 	# %h to the current hash (h gitweb parameter) and %b to the current
-	# hash base (hb gitweb parameter).
+	# hash base (hb gitweb parameter); %% expands to %.
 
 	# To enable system wide have in $GITWEB_CONFIG e.g.
 	# $feature{'actions'}{'default'} = [('graphiclog',
@@ -2866,14 +2866,19 @@ sub git_print_page_nav {
 	$arg{'tree'}{'hash_base'} = $treebase if defined $treebase;
 
 	my @actions = gitweb_check_feature('actions');
+	my %repl = (
+		'%' => '%',
+		'n' => $project,         # project name
+		'f' => $git_dir,         # project path within filesystem
+		'h' => $treehead || '',  # current hash ('h' parameter)
+		'b' => $treebase || '',  # hash base ('hb' parameter)
+	);
 	while (@actions) {
-		my ($label, $link, $pos) = (shift(@actions), shift(@actions), shift(@actions));
+		my ($label, $link, $pos) = splice(@actions,0,3);
+		# insert
 		@navs = map { $_ eq $pos ? ($_, $label) : $_ } @navs;
 		# munch munch
-		$link =~ s#%n#$project#g;
-		$link =~ s#%f#$git_dir#g;
-		$treehead ? $link =~ s#%h#$treehead#g : $link =~ s#%h##g;
-		$treebase ? $link =~ s#%b#$treebase#g : $link =~ s#%b##g;
+		$link =~ s/%([%nfhb])/$repl{$1}/g;
 		$arg{$label}{'_href'} = $link;
 	}
 
-- 
1.6.0.2.767.g8f0e