[3.12] gh-105820: Fix tok_mode expression buffer in file & readline tokenizer (GH-105828) (#105832)

(cherry picked from commit d382ad49157b3802fc5619f68d96810def517869)

Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>

1 files changed, 14 insertions, 1 deletions

diff --git a/Lib/test/test_fstring.py b/Lib/test/test_fstring.py
index cbb0308..8f6b576 100644
--- a/Lib/test/test_fstring.py
+++ b/Lib/test/test_fstring.py
@@ -15,7 +15,7 @@ import decimal
 import unittest
 from test import support
 from test.support.os_helper import temp_cwd
-from test.support.script_helper import assert_python_failure
+from test.support.script_helper import assert_python_failure, assert_python_ok
 
 a_global = 'global variable'
 
@@ -1635,5 +1635,18 @@ sdfsdfs{1+
                                 "f'{1=}{1;}'",
                             ])
 
+    def test_debug_in_file(self):
+        with temp_cwd():
+            script = 'script.py'
+            with open('script.py', 'w') as f:
+                f.write(f"""\
+print(f'''{{
+3
+=}}''')""")
+
+            _, stdout, _ = assert_python_ok(script)
+        self.assertEqual(stdout.decode('utf-8').strip().replace('\r\n', '\n').replace('\r', '\n'),
+                         "3\n=3")
+
 if __name__ == '__main__':
     unittest.main()