Initial checkin to test dealing with bad hierarchies (circular deps, for example).

diff --git a/t/011_infinite_loop.t b/t/011_infinite_loop.t
new file mode 100644 (file)
index 0000000..b466d9b
--- /dev/null
+++ b/t/011_infinite_loop.t
@@ -0,0 +1,127 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Test::More tests => 12;
+
+BEGIN {
+    use_ok('Algorithm::C3');
+}
+
+=pod
+
+This example is taken from: http://rt.cpan.org/Public/Bug/Display.html?id=20879
+
+               ---     ---     ---
+Level 5     8 | A | 9 | B | A | C |    (More General)
+               ---     ---     ---       V
+                  \     |     /          |
+                   \    |    /           |
+                    \   |   /            |
+                     \  |  /             |
+                       ---               |
+Level 4             7 | D |              |
+                       ---               |
+                      /   \              |
+                     /     \             |
+                  ---       ---          |
+Level 3        4 | G |   6 | E |         |
+                  ---       ---          |
+                   |         |           |
+                   |         |           |
+                  ---       ---          |
+Level 2        3 | H |   5 | F |         |
+                  ---       ---          |
+                      \   /  |           |
+                       \ /   |           |
+                        \    |           |
+                       / \   |           |
+                      /   \  |           |
+                  ---       ---          |
+Level 1        1 | J |   2 | I |         |
+                  ---       ---          |
+                    \       /            |
+                     \     /             |
+                       ---               v
+Level 0             0 | K |            (More Specialized)
+                       ---
+
+
+0123456789A
+KJIHGFEDABC
+
+=cut
+
+my $foo = {
+  k => [qw(j i)],
+  j => [qw(f)],
+  i => [qw(h f)],
+  h => [qw(g)],
+  g => [qw(d)],
+  f => [qw(e)],
+  e => [qw(f)],
+  d => [qw(a b c)],
+  c => [],
+  b => [],
+  a => [],
+};
+
+sub supers {
+  return @{ $foo->{ $_[0] } };
+}
+
+is_deeply(
+    [ Algorithm::C3::merge('a', \&supers) ],
+    [ qw(a) ],
+    '... got the right C3 merge order for a');
+
+is_deeply(
+    [ Algorithm::C3::merge('b', \&supers) ],
+    [ qw(b) ],
+    '... got the right C3 merge order for b');
+
+is_deeply(
+    [ Algorithm::C3::merge('c', \&supers) ],
+    [ qw(c) ],
+    '... got the right C3 merge order for c');
+
+is_deeply(
+    [ Algorithm::C3::merge('d', \&supers) ],
+    [ qw(d a b c) ],
+    '... got the right C3 merge order for d');
+
+is_deeply(
+    [ Algorithm::C3::merge('e', \&supers) ],
+    [ qw(e d a b c) ],
+    '... got the right C3 merge order for e');
+
+is_deeply(
+    [ Algorithm::C3::merge('f', \&supers) ],
+    [ qw(f e d a b c) ],
+    '... got the right C3 merge order for f');
+
+is_deeply(
+    [ Algorithm::C3::merge('g', \&supers) ],
+    [ qw(g d a b c) ],
+    '... got the right C3 merge order for g');
+
+is_deeply(
+    [ Algorithm::C3::merge('h', \&supers) ],
+    [ qw(h g d a b c) ],
+    '... got the right C3 merge order for h');
+
+is_deeply(
+    [ Algorithm::C3::merge('i', \&supers) ],
+    [ qw(i h g f e d a b c) ],
+    '... got the right C3 merge order for i');
+
+is_deeply(
+    [ Algorithm::C3::merge('j', \&supers) ],
+    [ qw(j f e d a b c) ],
+    '... got the right C3 merge order for j');
+
+is_deeply(
+    [ Algorithm::C3::merge('k', \&supers) ],
+    [ qw(k j i h g f e d a b c) ],
+    '... got the right C3 merge order for k');