[3.9] bpo-41604: Don't decrement the reference count of the previous user_ptr when set_panel_usertpr fails (pythonGH-21933).

madebr · serhiy-storchaka · commit e178858f3301 · 2021-01-31T20:54:19.000+02:00
(cherry picked from commit 3243e8a) Co-authored-by: Anonymous Maarten <madebr@users.noreply.github.com>
diff --git a/Misc/NEWS.d/next/Library/2020-08-21-15-24-14.bpo-41604.rTXleO.rst b/Misc/NEWS.d/next/Library/2020-08-21-15-24-14.bpo-41604.rTXleO.rst
@@ -0,0 +1,2 @@
+Don't decrement the reference count of the previous user_ptr when
+set_panel_userptr fails.
diff --git a/Modules/_curses_panel.c b/Modules/_curses_panel.c
@@ -440,7 +440,9 @@ _curses_panel_panel_set_userptr(PyCursesPanelObject *self, PyObject *obj)
         /* In case of an ncurses error, decref the new object again */
         Py_DECREF(obj);
     }
-    Py_XDECREF(oldobj);
+    else {
+        Py_XDECREF(oldobj);
+    }
     return PyCursesCheckERR(rc, "set_panel_userptr");
 }
 

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Don't decrement the reference count of the previous user_ptr when`
	`2`	`+set_panel_userptr fails.`
Original file line number	Diff line number	Diff line change
`@@ -440,7 +440,9 @@ _curses_panel_panel_set_userptr(PyCursesPanelObject self, PyObject obj)`
`440`	`440`	`/* In case of an ncurses error, decref the new object again */`
`441`	`441`	`Py_DECREF(obj);`
`442`	`442`	`}`
`443`		`- Py_XDECREF(oldobj);`
	`443`	`+ else {`
	`444`	`+ Py_XDECREF(oldobj);`
	`445`	`+ }`
`444`	`446`	`return PyCursesCheckERR(rc, "set_panel_userptr");`
`445`	`447`	`}`
`446`	`448`