1 files changed, 52 insertions, 1 deletions
diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
index 5c2a2af..358484d 100644
--- a/Lib/test/test_xml_etree.py
+++ b/Lib/test/test_xml_etree.py
@@ -758,7 +758,7 @@ class ElementTreeTest(unittest.TestCase):
             'mac-roman', 'mac-turkish',
             'iso2022-jp', 'iso2022-jp-1', 'iso2022-jp-2', 'iso2022-jp-2004',
             'iso2022-jp-3', 'iso2022-jp-ext',
-            'koi8-r', 'koi8-u',
+            'koi8-r', 'koi8-t', 'koi8-u', 'kz1048',
             'hz', 'ptcp154',
         ]
         for encoding in supported_encodings:
@@ -1666,6 +1666,57 @@ class BugsTest(unittest.TestCase):
         ET.register_namespace('test10777', 'http://myuri/')
         ET.register_namespace('test10777', 'http://myuri/')
 
+    def test_lost_text(self):
+        # Issue #25902: Borrowed text can disappear
+        class Text:
+            def __bool__(self):
+                e.text = 'changed'
+                return True
+
+        e = ET.Element('tag')
+        e.text = Text()
+        i = e.itertext()
+        t = next(i)
+        self.assertIsInstance(t, Text)
+        self.assertIsInstance(e.text, str)
+        self.assertEqual(e.text, 'changed')
+
+    def test_lost_tail(self):
+        # Issue #25902: Borrowed tail can disappear
+        class Text:
+            def __bool__(self):
+                e[0].tail = 'changed'
+                return True
+
+        e = ET.Element('root')
+        e.append(ET.Element('tag'))
+        e[0].tail = Text()
+        i = e.itertext()
+        t = next(i)
+        self.assertIsInstance(t, Text)
+        self.assertIsInstance(e[0].tail, str)
+        self.assertEqual(e[0].tail, 'changed')
+
+    def test_lost_elem(self):
+        # Issue #25902: Borrowed element can disappear
+        class Tag:
+            def __eq__(self, other):
+                e[0] = ET.Element('changed')
+                next(i)
+                return True
+
+        e = ET.Element('root')
+        e.append(ET.Element(Tag()))
+        e.append(ET.Element('tag'))
+        i = e.iter('tag')
+        try:
+            t = next(i)
+        except ValueError:
+            self.skipTest('generators are not reentrant')
+        self.assertIsInstance(t.tag, Tag)
+        self.assertIsInstance(e[0].tag, str)
+        self.assertEqual(e[0].tag, 'changed')
+
 
 # --------------------------------------------------------------------