[3.13] gh-87320: In the code module, handle exceptions raised in sys.…

…excepthook (GH-122456) (GH-122514)

Before, the exception caused by calling non-default sys.excepthook
in code.InteractiveInterpreter bubbled up to the caller, ending the REPL.
(cherry picked from commit bd3d31f)

Co-authored-by: CF Bolz-Tereick <cfbolz@gmx.de>

Lib/code.py

@@ -129,7 +129,7 @@ def showsyntaxerror(self, filename=None, **kwargs):
  else:
  # If someone has set sys.excepthook, we let that take precedence
  # over self.write
- sys.excepthook(type, value, tb)
+ self._call_excepthook(type, value, tb)
 
  def showtraceback(self, **kwargs):
  """Display the exception that just occurred.
@@ -144,16 +144,29 @@ def showtraceback(self, **kwargs):
  sys.last_traceback = last_tb
  sys.last_exc = ei[1]
  try:
- lines = traceback.format_exception(ei[0], ei[1], last_tb.tb_next, colorize=colorize)
  if sys.excepthook is sys.__excepthook__:
+ lines = traceback.format_exception(ei[0], ei[1], last_tb.tb_next, colorize=colorize)
  self.write(''.join(lines))
  else:
  # If someone has set sys.excepthook, we let that take precedence
  # over self.write
- sys.excepthook(ei[0], ei[1], last_tb)
+ self._call_excepthook(ei[0], ei[1], last_tb)
  finally:
  last_tb = ei = None
 
+ def _call_excepthook(self, typ, value, tb):
+ try:
+ sys.excepthook(typ, value, tb)
+ except SystemExit:
+ raise
+ except BaseException as e:
+ e.__context__ = None
+ print('Error in sys.excepthook:', file=sys.stderr)
+ sys.__excepthook__(type(e), e, e.__traceback__.tb_next)
+ print(file=sys.stderr)
+ print('Original exception was:', file=sys.stderr)
+ sys.__excepthook__(typ, value, tb)
+
  def write(self, data):
  """Write a string.
 

Lib/test/test_code_module.py

@@ -77,6 +77,39 @@ def test_sysexcepthook(self):
  self.console.interact()
  self.assertTrue(hook.called)
 
+ def test_sysexcepthook_crashing_doesnt_close_repl(self):
+ self.infunc.side_effect = ["1/0", "a = 123", "print(a)", EOFError('Finished')]
+ self.sysmod.excepthook = 1
+ self.console.interact()
+ self.assertEqual(['write', ('123', ), {}], self.stdout.method_calls[0])
+ error = "".join(call.args[0] for call in self.stderr.method_calls if call[0] == 'write')
+ self.assertIn("Error in sys.excepthook:", error)
+ self.assertEqual(error.count("'int' object is not callable"), 1)
+ self.assertIn("Original exception was:", error)
+ self.assertIn("division by zero", error)
+
+ def test_sysexcepthook_raising_BaseException(self):
+ self.infunc.side_effect = ["1/0", "a = 123", "print(a)", EOFError('Finished')]
+ s = "not so fast"
+ def raise_base(*args, **kwargs):
+ raise BaseException(s)
+ self.sysmod.excepthook = raise_base
+ self.console.interact()
+ self.assertEqual(['write', ('123', ), {}], self.stdout.method_calls[0])
+ error = "".join(call.args[0] for call in self.stderr.method_calls if call[0] == 'write')
+ self.assertIn("Error in sys.excepthook:", error)
+ self.assertEqual(error.count("not so fast"), 1)
+ self.assertIn("Original exception was:", error)
+ self.assertIn("division by zero", error)
+
+ def test_sysexcepthook_raising_SystemExit_gets_through(self):
+ self.infunc.side_effect = ["1/0"]
+ def raise_base(*args, **kwargs):
+ raise SystemExit
+ self.sysmod.excepthook = raise_base
+ with self.assertRaises(SystemExit):
+ self.console.interact()
+
  def test_banner(self):
  # with banner
  self.infunc.side_effect = EOFError('Finished')

Lib/test/test_pyrepl/test_pyrepl.py

@@ -1049,6 +1049,30 @@ def test_python_basic_repl(self):
  self.assertNotIn("Exception", output)
  self.assertNotIn("Traceback", output)
 
+ @force_not_colorized
+ def test_bad_sys_excepthook_doesnt_crash_pyrepl(self):
+ env = os.environ.copy()
+ commands = ("import sys\n"
+ "sys.excepthook = 1\n"
+ "1/0\n"
+ "exit()\n")
+
+ def check(output, exitcode):
+ self.assertIn("Error in sys.excepthook:", output)
+ self.assertEqual(output.count("'int' object is not callable"), 1)
+ self.assertIn("Original exception was:", output)
+ self.assertIn("division by zero", output)
+ self.assertEqual(exitcode, 0)
+ env.pop("PYTHON_BASIC_REPL", None)
+ output, exit_code = self.run_repl(commands, env=env)
+ if "can\'t use pyrepl" in output:
+ self.skipTest("pyrepl not available")
+ check(output, exit_code)
+
+ env["PYTHON_BASIC_REPL"] = "1"
+ output, exit_code = self.run_repl(commands, env=env)
+ check(output, exit_code)
+
  def test_not_wiping_history_file(self):
  # skip, if readline module is not available
  import_module('readline')

Misc/NEWS.d/next/Library/2024-07-30-14-46-16.gh-issue-87320.-Yk1wb.rst

@@ -0,0 +1,3 @@
+In :class:`code.InteractiveInterpreter`, handle exceptions caused by calling a
+non-default :func:`sys.excepthook`. Before, the exception bubbled up to the
+caller, ending the :term:`REPL`.