Issue #28070: Fixed parsing inline verbose flag in regular expressions.

Lib/sre_parse.py

@@ -847,6 +847,7 @@ def parse(str, flags=0, pattern=None):
         pattern = Pattern()
         pattern.flags = flags | SRE_FLAG_VERBOSE
         pattern.str = str
+        source.seek(0)
         p = _parse_sub(source, pattern, True, False)
 
     p.pattern.flags = fix_flags(str, p.pattern.flags)

Lib/test/test_re.py

@@ -1276,6 +1276,9 @@ class ReTests(unittest.TestCase):
         q = p.match(upper_char)
         self.assertTrue(q)
 
+        self.assertTrue(re.match('(?ixu) ' + upper_char, lower_char))
+        self.assertTrue(re.match('(?ixu) ' + lower_char, upper_char))
+
     def test_dollar_matches_twice(self):
         "$ matches the end of string, and just before the terminating \n"
         pattern = re.compile('$')

Misc/NEWS

@@ -138,6 +138,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #28070: Fixed parsing inline verbose flag in regular expressions.
+
 - Issue #19500: Add client-side SSL session resumption to the ssl module.
 
 - Issue #28022: Deprecate ssl-related arguments in favor of SSLContext. The