Added assertXML[Not]Equal assertions

This is especially needed to compare XML when hash randomization
is on, as attribute order may vary. Refs #17758, #19038.
Thanks Taylor Mitchell for the initial patch, and Ian Clelland for
review and cleanup.

docs/releases/1.5.txt

@@ -198,6 +198,11 @@ Django 1.5 also includes several smaller improvements worth noting:
 * The loaddata management command now supports an `ignorenonexistent` option to
   ignore data for fields that no longer exist.
 
+* :meth:`~django.test.SimpleTestCase.assertXMLEqual` and
+  :meth:`~django.test.SimpleTestCase.assertXMLNotEqual` new assertions allow
+  you to test equality for XML content at a semantic level, without caring for
+  syntax differences (spaces, attribute order, etc.).
+
 Backwards incompatible changes in 1.5
 =====================================
 

docs/topics/testing.txt

@@ -1783,6 +1783,25 @@ your test suite.
     ``html1`` and ``html2`` must be valid HTML. An ``AssertionError`` will be
     raised if one of them cannot be parsed.
 
+.. method:: SimpleTestCase.assertXMLEqual(xml1, xml2, msg=None)
+
+    .. versionadded:: 1.5
+
+    Asserts that the strings ``xml1`` and ``xml2`` are equal. The
+    comparison is based on XML semantics. Similarily to
+    :meth:`~SimpleTestCase.assertHTMLEqual`, the comparison is
+    made on parsed content, hence only semantic differences are considered, not
+    syntax differences. When unvalid XML is passed in any parameter, an
+    ``AssertionError`` is always raised, even if both string are identical.
+
+.. method:: SimpleTestCase.assertXMLNotEqual(xml1, xml2, msg=None)
+
+    .. versionadded:: 1.5
+
+    Asserts that the strings ``xml1`` and ``xml2`` are *not* equal. The
+    comparison is based on XML semantics. See
+    :meth:`~SimpleTestCase.assertXMLEqual` for details.
+
 .. _topics-testing-email:
 
 Email services