Issue #25455: Fixed a crash in repr of ElementTree.Element with recursive tag.

1 files changed, 7 insertions, 1 deletions

diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
index 44e3142dc9..bc1dd1461b 100644
--- a/Lib/test/test_xml_etree.py
+++ b/Lib/test/test_xml_etree.py
@@ -18,7 +18,7 @@ import weakref
 
 from itertools import product
 from test import support
-from test.support import TESTFN, findfile, import_fresh_module, gc_collect
+from test.support import TESTFN, findfile, import_fresh_module, gc_collect, swap_attr
 
 # pyET is the pure-Python implementation.
 #
@@ -1860,6 +1860,12 @@ class BadElementTest(ElementTestCase, unittest.TestCase):
         e.extend([ET.Element('bar')])
         self.assertRaises(ValueError, e.remove, X('baz'))
 
+    def test_recursive_repr(self):
+        # Issue #25455
+        e = ET.Element('foo')
+        with swap_attr(e, 'tag', e):
+            with self.assertRaises(RuntimeError):
+                repr(e)  # Should not crash
 
 class MutatingElementPath(str):
     def __new__(cls, elem, *args):