1 files changed, 174 insertions, 1 deletions
diff --git a/perl/Git/SVN/Utils.pm b/perl/Git/SVN/Utils.pm
index 496006bc7b..8b8cf3755c 100644
--- a/perl/Git/SVN/Utils.pm
+++ b/perl/Git/SVN/Utils.pm
@@ -3,9 +3,18 @@ package Git::SVN::Utils;
 use strict;
 use warnings;
 
+use SVN::Core;
+
 use base qw(Exporter);
 
-our @EXPORT_OK = qw(fatal can_compress);
+our @EXPORT_OK = qw(
+	fatal
+	can_compress
+	canonicalize_path
+	canonicalize_url
+	join_paths
+	add_path_to_url
+);
 
 
 =head1 NAME
@@ -56,4 +65,168 @@ sub can_compress {
 }
 
 
+=head3 canonicalize_path
+
+    my $canoncalized_path = canonicalize_path($path);
+
+Converts $path into a canonical form which is safe to pass to the SVN
+API as a file path.
+
+=cut
+
+# Turn foo/../bar into bar
+sub _collapse_dotdot {
+	my $path = shift;
+
+	1 while $path =~ s{/[^/]+/+\.\.}{};
+	1 while $path =~ s{[^/]+/+\.\./}{};
+	1 while $path =~ s{[^/]+/+\.\.}{};
+
+	return $path;
+}
+
+
+sub canonicalize_path {
+	my $path = shift;
+	my $rv;
+
+	# The 1.7 way to do it
+	if ( defined &SVN::_Core::svn_dirent_canonicalize ) {
+		$path = _collapse_dotdot($path);
+		$rv = SVN::_Core::svn_dirent_canonicalize($path);
+	}
+	# The 1.6 way to do it
+	# This can return undef on subversion-perl-1.4.2-2.el5 (CentOS 5.2)
+	elsif ( defined &SVN::_Core::svn_path_canonicalize ) {
+		$path = _collapse_dotdot($path);
+		$rv = SVN::_Core::svn_path_canonicalize($path);
+	}
+
+	return $rv if defined $rv;
+
+	# No SVN API canonicalization is available, or the SVN API
+	# didn't return a successful result, do it ourselves
+	return _canonicalize_path_ourselves($path);
+}
+
+
+sub _canonicalize_path_ourselves {
+	my ($path) = @_;
+	my $dot_slash_added = 0;
+	if (substr($path, 0, 1) ne "/") {
+		$path = "./" . $path;
+		$dot_slash_added = 1;
+	}
+	$path =~ s#/+#/#g;
+	$path =~ s#/\.(?:/|$)#/#g;
+	$path = _collapse_dotdot($path);
+	$path =~ s#/$##g;
+	$path =~ s#^\./## if $dot_slash_added;
+	$path =~ s#^\.$##;
+	return $path;
+}
+
+
+=head3 canonicalize_url
+
+    my $canonicalized_url = canonicalize_url($url);
+
+Converts $url into a canonical form which is safe to pass to the SVN
+API as a URL.
+
+=cut
+
+sub canonicalize_url {
+	my $url = shift;
+
+	# The 1.7 way to do it
+	if ( defined &SVN::_Core::svn_uri_canonicalize ) {
+		return SVN::_Core::svn_uri_canonicalize($url);
+	}
+	# There wasn't a 1.6 way to do it, so we do it ourself.
+	else {
+		return _canonicalize_url_ourselves($url);
+	}
+}
+
+
+sub _canonicalize_url_path {
+	my ($uri_path) = @_;
+
+	my @parts;
+	foreach my $part (split m{/+}, $uri_path) {
+		$part =~ s/([^~\w.%+-]|%(?![a-fA-F0-9]{2}))/sprintf("%%%02X",ord($1))/eg;
+		push @parts, $part;
+	}
+
+	return join('/', @parts);
+}
+
+sub _canonicalize_url_ourselves {
+	my ($url) = @_;
+	if ($url =~ m#^([^:]+)://([^/]*)(.*)$#) {
+		my ($scheme, $domain, $uri) = ($1, $2, _canonicalize_url_path(canonicalize_path($3)));
+		$url = "$scheme://$domain$uri";
+	}
+	$url;
+}
+
+
+=head3 join_paths
+
+    my $new_path = join_paths(@paths);
+
+Appends @paths together into a single path.  Any empty paths are ignored.
+
+=cut
+
+sub join_paths {
+	my @paths = @_;
+
+	@paths = grep { defined $_ && length $_ } @paths;
+
+	return '' unless @paths;
+	return $paths[0] if @paths == 1;
+
+	my $new_path = shift @paths;
+	$new_path =~ s{/+$}{};
+
+	my $last_path = pop @paths;
+	$last_path =~ s{^/+}{};
+
+	for my $path (@paths) {
+		$path =~ s{^/+}{};
+		$path =~ s{/+$}{};
+		$new_path .= "/$path";
+	}
+
+	return $new_path .= "/$last_path";
+}
+
+
+=head3 add_path_to_url
+
+    my $new_url = add_path_to_url($url, $path);
+
+Appends $path onto the $url.  If $path is empty, $url is returned unchanged.
+
+=cut
+
+sub add_path_to_url {
+	my($url, $path) = @_;
+
+	return $url if !defined $path or !length $path;
+
+	# Strip trailing and leading slashes so we don't
+	# wind up with http://x.com///path
+	$url  =~ s{/+$}{};
+	$path =~ s{^/+}{};
+
+	# If a path has a % in it, URI escape it so it's not
+	# mistaken for a URI escape later.
+	$path =~ s{%}{%25}g;
+
+	return join '/', $url, $path;
+}
+
 1;