From b9cd72a9f776bc2b517e22af444dc14268f50b41 Mon Sep 17 00:00:00 2001
From: Georg Brandl <georg@python.org>
Date: Fri, 15 Oct 2010 17:58:45 +0000
Subject: [PATCH] #5762: fix handling of empty namespace in minidom, which
 would result in AttributeError on toxml().

---
 Lib/test/test_minidom.py | 7 +++++++
 Lib/xml/dom/minidom.py   | 7 ++++---
 Misc/NEWS                | 3 +++
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_minidom.py b/Lib/test/test_minidom.py
index d9d3be49c84..97668d343cb 100644
--- a/Lib/test/test_minidom.py
+++ b/Lib/test/test_minidom.py
@@ -1489,6 +1489,13 @@ class MinidomTest(unittest.TestCase):
         doc.appendChild(doc.createComment("foo--bar"))
         self.assertRaises(ValueError, doc.toxml)
 
+    def testEmptyXMLNSValue(self):
+        doc = parseString("<element xmlns=''>\n"
+                          "<foo/>\n</element>")
+        doc2 = parseString(doc.toxml())
+        self.confirm(doc2.namespaceURI == xml.dom.EMPTY_NAMESPACE)
+
+
 def test_main():
     run_unittest(MinidomTest)
 
diff --git a/Lib/xml/dom/minidom.py b/Lib/xml/dom/minidom.py
index 1beae0cffa5..81a1330c603 100644
--- a/Lib/xml/dom/minidom.py
+++ b/Lib/xml/dom/minidom.py
@@ -301,9 +301,10 @@ def _in_document(node):
 
 def _write_data(writer, data):
     "Writes datachars to writer."
-    data = data.replace("&", "&amp;").replace("<", "&lt;")
-    data = data.replace("\"", "&quot;").replace(">", "&gt;")
-    writer.write(data)
+    if data:
+        data = data.replace("&", "&amp;").replace("<", "&lt;"). \
+                    replace("\"", "&quot;").replace(">", "&gt;")
+        writer.write(data)
 
 def _get_elements_by_tagName_helper(parent, name, rc):
     for node in parent.childNodes:
diff --git a/Misc/NEWS b/Misc/NEWS
index 097edd20ee7..4bb89da9a6a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -24,6 +24,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #5762: Fix AttributeError raised by ``xml.dom.minidom`` when an empty
+  XML namespace attribute is encountered.
+
 - Issue #2830: Add the ``html.escape()`` function, which quotes all problematic
   characters by default.  Deprecate ``cgi.escape()``.