Issue #14936: curses_panel was converted to PEP 3121 API.

Patch by Robin Schreiber.

Misc/NEWS

@@ -21,6 +21,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #14936: curses_panel was converted to PEP 3121 API.
+  Patch by Robin Schreiber.
+
 - Issue #1667546: On platforms supporting tm_zone and tm_gmtoff fields
   in struct tm, time.struct_time objects returned by time.gmtime(),
   time.localtime() and time.strptime() functions now have tm_zone and

Modules/_curses_panel.c

@@ -16,8 +16,38 @@ static char *PyCursesVersion = "2.1";
 
 #include <panel.h>
 
-static PyObject *PyCursesError;
+typedef struct {
+    PyObject *PyCursesError;
+} _curses_panelstate;
 
+#define _curses_panelstate(o) ((_curses_panelstate *)PyModule_GetState(o))
+
+/*static PyObject *PyCursesError;*/
+
+static int
+_curses_panel_clear(PyObject *m)
+{
+    Py_CLEAR(_curses_panelstate(m)->PyCursesError);
+    return 0;
+}
+
+static int
+_curses_panel_traverse(PyObject *m, visitproc visit, void *arg)
+{
+    Py_VISIT(_curses_panelstate(m)->PyCursesError);
+    return 0;
+}
+
+static void
+_curses_panel_free(void *m)
+{
+    _curses_panel_clear((PyObject *) m);
+}
+
+static struct PyModuleDef _curses_panelmodule;
+
+#define _curses_panelstate_global \
+((_curses_panelstate *) PyModule_GetState(PyState_FindModule(&_curses_panelmodule)))
 
 /* Utility Functions */
 
@@ -34,9 +64,9 @@ PyCursesCheckERR(int code, char *fname)
         return Py_None;
     } else {
         if (fname == NULL) {
-            PyErr_SetString(PyCursesError, catchall_ERR);
+            PyErr_SetString(_curses_panelstate_global->PyCursesError, catchall_ERR);
         } else {
-            PyErr_Format(PyCursesError, "%s() returned ERR", fname);
+            PyErr_Format(_curses_panelstate_global->PyCursesError, "%s() returned ERR", fname);
         }
         return NULL;
     }
@@ -280,7 +310,7 @@ PyCursesPanel_replace_panel(PyCursesPanelObject *self, PyObject *args)
 
     rtn = replace_panel(self->pan, temp->win);
     if (rtn == ERR) {
-        PyErr_SetString(PyCursesError, "replace_panel() returned ERR");
+        PyErr_SetString(_curses_panelstate_global->PyCursesError, "replace_panel() returned ERR");
         return NULL;
     }
     Py_DECREF(po->wo);
@@ -305,7 +335,7 @@ PyCursesPanel_userptr(PyCursesPanelObject *self)
     PyCursesInitialised;
     obj = (PyObject *) panel_userptr(self->pan);
     if (obj == NULL) {
-        PyErr_SetString(PyCursesError, "no userptr set");
+        PyErr_SetString(_curses_panelstate_global->PyCursesError, "no userptr set");
         return NULL;
     }
 
@@ -405,7 +435,7 @@ PyCurses_new_panel(PyObject *self, PyObject *args)
         return NULL;
     pan = new_panel(win->win);
     if (pan == NULL) {
-        PyErr_SetString(PyCursesError, catchall_NULL);
+        PyErr_SetString(_curses_panelstate_global->PyCursesError, catchall_NULL);
         return NULL;
     }
     return (PyObject *)PyCursesPanel_New(pan, win);
@@ -467,12 +497,12 @@ static struct PyModuleDef _curses_panelmodule = {
         PyModuleDef_HEAD_INIT,
         "_curses_panel",
         NULL,
-        -1,
+        sizeof(_curses_panelstate),
         PyCurses_methods,
         NULL,
-        NULL,
-        NULL,
-        NULL
+        _curses_panel_traverse,
+        _curses_panel_clear,
+        _curses_panel_free
 };
 
 PyMODINIT_FUNC
@@ -493,8 +523,8 @@ PyInit__curses_panel(void)
     d = PyModule_GetDict(m);
 
     /* For exception _curses_panel.error */
-    PyCursesError = PyErr_NewException("_curses_panel.error", NULL, NULL);
-    PyDict_SetItemString(d, "error", PyCursesError);
+    _curses_panelstate(m)->PyCursesError = PyErr_NewException("_curses_panel.error", NULL, NULL);
+    PyDict_SetItemString(d, "error", _curses_panelstate(m)->PyCursesError);
 
     /* Make the version available */
     v = PyUnicode_FromString(PyCursesVersion);