#18113: avoid segfault if Py_XDECREF triggers code that calls set_panel_userptr again
Problem noted & original patch by Serhiy Storchaka; I tweaked the patch a bit.
diff --git a/Lib/test/test_curses.py b/Lib/test/test_curses.py
index 76812b7..7310afc 100644
--- a/Lib/test/test_curses.py
+++ b/Lib/test/test_curses.py
@@ -264,6 +264,14 @@
if sys.getrefcount(obj) != nrefs:
raise RuntimeError("set_userptr leaked references")
+def test_userptr_segfault(stdscr):
+ panel = curses.panel.new_panel(stdscr)
+ class A:
+ def __del__(self):
+ panel.set_userptr(None)
+ panel.set_userptr(A())
+ panel.set_userptr(None)
+
def test_resize_term(stdscr):
if hasattr(curses, 'resizeterm'):
lines, cols = curses.LINES, curses.COLS
@@ -330,6 +338,7 @@
window_funcs(stdscr)
test_userptr_without_set(stdscr)
test_userptr_memory_leak(stdscr)
+ test_userptr_segfault(stdscr)
test_resize_term(stdscr)
test_issue6243(stdscr)
test_unget_wch(stdscr)
diff --git a/Modules/_curses_panel.c b/Modules/_curses_panel.c
index c11f3d8..f560702 100644
--- a/Modules/_curses_panel.c
+++ b/Modules/_curses_panel.c
@@ -323,12 +323,17 @@
PyCursesPanel_set_panel_userptr(PyCursesPanelObject *self, PyObject *obj)
{
PyObject *oldobj;
+ int rc;
PyCursesInitialised;
- oldobj = (PyObject *) panel_userptr(self->pan);
- Py_XDECREF(oldobj);
Py_INCREF(obj);
- return PyCursesCheckERR(set_panel_userptr(self->pan, (void*)obj),
- "set_panel_userptr");
+ oldobj = (PyObject *) panel_userptr(self->pan);
+ rc = set_panel_userptr(self->pan, (void*)obj);
+ if (rc == ERR) {
+ /* In case of an ncurses error, decref the new object again */
+ Py_DECREF(obj);
+ }
+ Py_XDECREF(oldobj);
+ return PyCursesCheckERR(rc, "set_panel_userptr");
}
static PyObject *