git-svn: introduce add_path_to_url function

Remove the ad-hoc versions.

This is mostly to normalize the process and ensure the URLs produced
don't have double slashes or anything.

Also provides a place to fix the corner case where a file path
contains a percent sign.

[ew: commit title]

Signed-off-by: Eric Wong <normalperson@yhbt.net>

t/Git-SVN/Utils/add_path_to_url.t

@@ -0,0 +1,27 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+use Test::More 'no_plan';
+
+use Git::SVN::Utils qw(
+	add_path_to_url
+);
+
+# A reference cannot be a hash key, so we use an array.
+my @tests = (
+	["http://x.com", "bar"]			=> 'http://x.com/bar',
+	["http://x.com", ""]			=> 'http://x.com',
+	["http://x.com/foo/", undef]		=> 'http://x.com/foo/',
+	["http://x.com/foo/", "/bar/baz/"]	=> 'http://x.com/foo/bar/baz/',
+	["http://x.com", 'per%cent']		=> 'http://x.com/per%25cent',
+);
+
+while(@tests) {
+	my($have, $want) = splice @tests, 0, 2;
+
+	my $args = join ", ", map { qq['$_'] } map { defined($_) ? $_ : 'undef' } @$have;
+	my $name = "add_path_to_url($args) eq $want";
+	is add_path_to_url(@$have), $want, $name;
+}