Skip to content

[3.11] gh-113358: Fix rendering tracebacks with exceptions with a broken __getattr__ (GH-113359) #114118

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 7 commits into from
Jan 19, 2024
Merged

[3.11] gh-113358: Fix rendering tracebacks with exceptions with a broken __getattr__ (GH-113359) #114118

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
8c12e96
gh-113358: Fix rendering tracebacks with exceptions with a broken __g…
perrinjerome Jan 16, 2024
67ac054
Address review comments
perrinjerome Jan 17, 2024
2c882e0
Apply suggestions from code review
iritkatriel Jan 17, 2024
a4613e2
fix reference leak, after PyErr_Fetch we own the references
perrinjerome Jan 17, 2024
25d62fb
move PyList_New as suggested
perrinjerome Jan 19, 2024
618d128
fixup! move PyList_New as suggested
perrinjerome Jan 19, 2024
d72e989
address review comments
perrinjerome Jan 19, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 15 additions & 0 deletions Lib/test/test_traceback.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1601,6 +1601,21 @@ def __repr__(self):
err_msg = '<note str() failed>'
self.assertEqual(self.get_report(e), vanilla + err_msg + '\nFinal Note\n')

# an exception with a broken __getattr__ raising a non expected error
class BrokenException(Exception):
broken = False
def __getattr__(self, name):
if self.broken:
raise ValueError(f'no {name}')
raise AttributeError(name)

e = BrokenException(123)
vanilla = self.get_report(e)
e.broken = True
self.assertEqual(
self.get_report(e),
vanilla + "Ignored error getting __notes__: ValueError('no __notes__')\n")

def test_exception_with_multiple_notes(self):
for e in [ValueError(42), SyntaxError('bad syntax')]:
with self.subTest(e=e):
Expand Down
6 changes: 5 additions & 1 deletion Lib/traceback.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -733,7 +733,11 @@ def __init__(self, exc_type, exc_value, exc_traceback, *, limit=None,
# Capture now to permit freeing resources: only complication is in the
# unofficial API _format_final_exc_line
self._str = _safe_string(exc_value, 'exception')
self.__notes__ = getattr(exc_value, '__notes__', None)
try:
self.__notes__ = getattr(exc_value, '__notes__', None)
except Exception as e:
self.__notes__ = [
f'Ignored error getting __notes__: {_safe_string(e, "__notes__", repr)}']

if exc_type and issubclass(exc_type, SyntaxError):
# Handle SyntaxError's specially
Expand Down
1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Library/2023-12-21-14-55-06.gh-issue-113358.nRkiSL.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Fix rendering tracebacks for exceptions with a broken ``__getattr__``.
32 changes: 31 additions & 1 deletion Python/pythonrun.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1199,6 +1199,36 @@ print_exception_notes(struct exception_print_context *ctx, PyObject *notes)
return -1;
}

static int
get_exception_notes(struct exception_print_context *ctx, PyObject *value, PyObject **notes) {
PyObject *note = NULL;

if (_PyObject_LookupAttr(value, &_Py_ID(__notes__), notes) < 0) {
PyObject *type, *errvalue, *tback;
PyErr_Fetch(&type, &errvalue, &tback);
note = PyUnicode_FromFormat("Ignored error getting __notes__: %R", errvalue);
Py_XDECREF(type);
Py_XDECREF(errvalue);
Py_XDECREF(tback);
if (!note) {
goto error;
}
*notes = PyList_New(1);
if (!*notes) {
goto error;
}
if (PyList_SetItem(*notes, 0, note) < 0) {
Py_DECREF(*notes);
goto error;
}
}

return 0;
error:
Py_XDECREF(note);
return -1;
}

static int
print_exception(struct exception_print_context *ctx, PyObject *value)
{
Expand All @@ -1218,7 +1248,7 @@ print_exception(struct exception_print_context *ctx, PyObject *value)

/* grab the type and notes now because value can change below */
PyObject *type = (PyObject *) Py_TYPE(value);
if (_PyObject_LookupAttr(value, &_Py_ID(__notes__), &notes) < 0) {
if (get_exception_notes(ctx, value, &notes) < 0) {
goto error;
}

Expand Down