pythongh-124703: Change back to raising bdb.BdbQuit when exiting pdb in 'inline' mode in a REPL session (python#130395)

Author: ADThomas-astro

Lib/pdb.py

@@ -1758,7 +1758,10 @@ def do_quit(self, arg):
 
         Quit from the debugger. The program being executed is aborted.
         """
-        if self.mode == 'inline':
+        # Show prompt to kill process when in 'inline' mode and if pdb was not
+        # started from an interactive console. The attribute sys.ps1 is only
+        # defined if the interpreter is in interactive mode.
+        if self.mode == 'inline' and not hasattr(sys, 'ps1'):
             while True:
                 try:
                     reply = input('Quitting pdb will kill the process. Quit anyway? [y/n] ')

Lib/test/test_pdb.py

@@ -19,6 +19,7 @@
 from test.support import force_not_colorized, os_helper
 from test.support.import_helper import import_module
 from test.support.pty_helper import run_pty, FakeInput
+from test.support.script_helper import kill_python
 from unittest.mock import patch
 
 SKIP_CORO_TESTS = False
@@ -4342,6 +4343,29 @@ def test_quit(self):
         self.assertEqual(stdout.count("Quit anyway"), 2)
 
 
+@support.force_not_colorized_test_class
+@support.requires_subprocess()
+class TestREPLSession(unittest.TestCase):
+    def test_return_from_inline_mode_to_REPL(self):
+        # GH-124703: Raise BdbQuit when exiting pdb in REPL session.
+        # This allows the REPL session to continue.
+        from test.test_repl import spawn_repl
+        p = spawn_repl()
+        user_input = """
+            x = 'Spam'
+            import pdb
+            pdb.set_trace(commands=['x + "During"', 'q'])
+            x + 'After'
+        """
+        p.stdin.write(textwrap.dedent(user_input))
+        output = kill_python(p)
+        self.assertIn('SpamDuring', output)
+        self.assertNotIn("Quit anyway", output)
+        self.assertIn('BdbQuit', output)
+        self.assertIn('SpamAfter', output)
+        self.assertEqual(p.returncode, 0)
+
+
 @support.requires_subprocess()
 class PdbTestReadline(unittest.TestCase):
     def setUpClass():

Misc/NEWS.d/next/Library/2025-02-21-09-05-44.gh-issue-124703.AMJD4Y.rst

@@ -0,0 +1 @@
+Executing ``quit`` command in :mod:`pdb` will raise :exc:`bdb.BdbQuit` when :mod:`pdb` is started from an interactive console using :func:`breakpoint` or :func:`pdb.set_trace`.