Handle deleted wiki page versions (#10852).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@10684 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/unit/wiki_content_test.rb

@@ -122,4 +122,42 @@ class WikiContentTest < ActiveSupport::TestCase
     assert_equal true, content.versions.first(:order => 'version DESC').current_version?
     assert_equal false, content.versions.first(:order => 'version ASC').current_version?
   end
+
+  def test_previous_for_first_version_should_return_nil
+    content = WikiContent::Version.find_by_page_id_and_version(1, 1)
+    assert_nil content.previous
+  end
+
+  def test_previous_for_version_should_return_previous_version
+    content = WikiContent::Version.find_by_page_id_and_version(1, 3)
+    assert_not_nil content.previous
+    assert_equal 2, content.previous.version
+  end
+
+  def test_previous_for_version_with_gap_should_return_previous_available_version
+    WikiContent::Version.find_by_page_id_and_version(1, 2).destroy
+
+    content = WikiContent::Version.find_by_page_id_and_version(1, 3)
+    assert_not_nil content.previous
+    assert_equal 1, content.previous.version
+  end
+
+  def test_next_for_last_version_should_return_nil
+    content = WikiContent::Version.find_by_page_id_and_version(1, 3)
+    assert_nil content.next
+  end
+
+  def test_next_for_version_should_return_next_version
+    content = WikiContent::Version.find_by_page_id_and_version(1, 1)
+    assert_not_nil content.next
+    assert_equal 2, content.next.version
+  end
+
+  def test_next_for_version_with_gap_should_return_next_available_version
+    WikiContent::Version.find_by_page_id_and_version(1, 2).destroy
+
+    content = WikiContent::Version.find_by_page_id_and_version(1, 1)
+    assert_not_nil content.next
+    assert_equal 3, content.next.version
+  end
 end