[3.13] gh-67877: Fix memory leaks in terminated RE matching (GH-126840) (GH-126960)

If SRE(match) function terminates abruptly, either because of a signal
or because memory allocation fails, allocated SRE_REPEAT blocks might
be never released.

Co-authored-by: <wjssz@users.noreply.github.com>
(cherry picked from commit 7538e7f569)

Lib/test/test_re.py

@@ -2664,6 +2664,47 @@ class ReTests(unittest.TestCase):
     def test_fail(self):
         self.assertEqual(re.search(r'12(?!)|3', '123')[0], '3')
 
+    def test_character_set_any(self):
+        # The union of complementary character sets matches any character
+        # and is equivalent to "(?s:.)".
+        s = '1x\n'
+        for p in r'[\s\S]', r'[\d\D]', r'[\w\W]', r'[\S\s]', r'\s|\S':
+            with self.subTest(pattern=p):
+                self.assertEqual(re.findall(p, s), list(s))
+                self.assertEqual(re.fullmatch('(?:' + p + ')+', s).group(), s)
+
+    def test_character_set_none(self):
+        # Negation of the union of complementary character sets does not match
+        # any character.
+        s = '1x\n'
+        for p in r'[^\s\S]', r'[^\d\D]', r'[^\w\W]', r'[^\S\s]':
+            with self.subTest(pattern=p):
+                self.assertIsNone(re.search(p, s))
+                self.assertIsNone(re.search('(?s:.)' + p, s))
+
+    def check_interrupt(self, pattern, string, maxcount):
+        class Interrupt(Exception):
+            pass
+        p = re.compile(pattern)
+        for n in range(maxcount):
+            try:
+                p._fail_after(n, Interrupt)
+                p.match(string)
+                return n
+            except Interrupt:
+                pass
+            finally:
+                p._fail_after(-1, None)
+
+    @unittest.skipUnless(hasattr(re.Pattern, '_fail_after'), 'requires debug build')
+    def test_memory_leaks(self):
+        self.check_interrupt(r'(.)*:', 'abc:', 100)
+        self.check_interrupt(r'([^:])*?:', 'abc:', 100)
+        self.check_interrupt(r'([^:])*+:', 'abc:', 100)
+        self.check_interrupt(r'(.){2,4}:', 'abc:', 100)
+        self.check_interrupt(r'([^:]){2,4}?:', 'abc:', 100)
+        self.check_interrupt(r'([^:]){2,4}+:', 'abc:', 100)
+
 
 def get_debug_out(pat):
     with captured_stdout() as out: