From 753b67c58de8021487af7cafa4241e8326aa5508 Mon Sep 17 00:00:00 2001
From: Caio Ariede <caio.ariede@gmail.com>
Date: Wed, 22 May 2019 10:31:46 -0300
Subject: [PATCH] Fixed #30497 -- Ignored document type in
 assertXMLEqual()/assertXMLNotEqual().

---
 django/test/utils.py          | 5 +++--
 docs/topics/testing/tools.txt | 4 ++--
 tests/test_utils/tests.py     | 5 +++++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/django/test/utils.py b/django/test/utils.py
index 3a630a8109..819e423326 100644
--- a/django/test/utils.py
+++ b/django/test/utils.py
@@ -537,7 +537,8 @@ def compare_xml(want, got):
     """
     Try to do a 'xml-comparison' of want and got. Plain string comparison
     doesn't always work because, for example, attribute ordering should not be
-    important. Ignore comment nodes and leading and trailing whitespace.
+    important. Ignore comment nodes, document type node, and leading and
+    trailing whitespaces.
 
     Based on https://github.com/lxml/lxml/blob/master/src/lxml/doctestcompare.py
     """
@@ -575,7 +576,7 @@ def compare_xml(want, got):
 
     def first_node(document):
         for node in document.childNodes:
-            if node.nodeType != Node.COMMENT_NODE:
+            if node.nodeType not in (Node.COMMENT_NODE, Node.DOCUMENT_TYPE_NODE):
                 return node
 
     want = want.strip().replace('\\n', '\n')
diff --git a/docs/topics/testing/tools.txt b/docs/topics/testing/tools.txt
index dd96981504..ad31c0bb9f 100644
--- a/docs/topics/testing/tools.txt
+++ b/docs/topics/testing/tools.txt
@@ -1645,8 +1645,8 @@ your test suite.
     syntax differences. When invalid XML is passed in any parameter, an
     ``AssertionError`` is always raised, even if both string are identical.
 
-    XML declaration and comments are ignored. Only the root element and its
-    children are compared.
+    XML declaration, document type, and comments are ignored. Only the root
+    element and its children are compared.
 
     Output in case of error can be customized with the ``msg`` argument.
 
diff --git a/tests/test_utils/tests.py b/tests/test_utils/tests.py
index f07c0dcd53..32007ebeb2 100644
--- a/tests/test_utils/tests.py
+++ b/tests/test_utils/tests.py
@@ -920,6 +920,11 @@ class XMLEqualTests(SimpleTestCase):
         xml2 = "<elem>foo</elem> <elem>bar</elem>"
         self.assertXMLNotEqual(xml1, xml2)
 
+    def test_doctype_root(self):
+        xml1 = '<?xml version="1.0"?><!DOCTYPE root SYSTEM "example1.dtd"><root />'
+        xml2 = '<?xml version="1.0"?><!DOCTYPE root SYSTEM "example2.dtd"><root />'
+        self.assertXMLEqual(xml1, xml2)
+
 
 class SkippingExtraTests(TestCase):
     fixtures = ['should_not_be_loaded.json']