gh-109617: fix ncurses incompatibility on macOS with Xcode 15

Include/py_curses.h

@@ -23,7 +23,7 @@
 # endif
 #endif
 
-#if !defined(HAVE_CURSES_IS_PAD) && defined(WINDOW_HAS_FLAGS)
+#if defined(WINDOW_HAS_FLAGS)
 /* The following definition is necessary for ncurses 5.7; without it,
    some of [n]curses.h set NCURSES_OPAQUE to 1, and then Python
    can't get at the WINDOW flags field. */
@@ -39,7 +39,8 @@
 #ifdef HAVE_NCURSES_H
 /* configure was checking <curses.h>, but we will
    use <ncurses.h>, which has some or all these features. */
-#if !defined(WINDOW_HAS_FLAGS) && !(NCURSES_OPAQUE+0)
+#if !defined(WINDOW_HAS_FLAGS) && \
+    (NCURSES_VERSION_PATCH+0 < 20070303 || !(NCURSES_OPAQUE+0))
 #define WINDOW_HAS_FLAGS 1
 #endif
 #if !defined(HAVE_CURSES_IS_PAD) && NCURSES_VERSION_PATCH+0 >= 20090906

Misc/NEWS.d/next/Library/2023-10-24-12-39-04.gh-issue-109617.YoI8TV.rst

@@ -0,0 +1,2 @@
+:mod:`ncurses`: fixed a crash that could occur on macOS 13 or earlier when
+Python was built with Apple Xcode 15's SDK.

Modules/_cursesmodule.c

@@ -1155,11 +1155,19 @@ int py_mvwdelch(WINDOW *w, int y, int x)
 }
 #endif
 
+static inline bool
+py_is_pad(const WINDOW *win) {
 #if defined(HAVE_CURSES_IS_PAD)
-#define py_is_pad(win)      is_pad(win)
-#elif defined(WINDOW_HAS_FLAGS)
-#define py_is_pad(win)      ((win) ? ((win)->_flags & _ISPAD) != 0 : FALSE)
+    // is_pad is defined, either as a macro or as a function
+    return is_pad(win);
+#elif WINDOW_HAS_FLAGS
+    // is_pad is not defined, but we can inspect struct internals
+    return (win ? (win->_flags & _ISPAD) != 0 : FALSE);
+#else
+    // probably not ncurses
+    return FALSE;
 #endif
+}
 
 /* chgat, added by Fabian Kreutz <fabian.kreutz at gmx.net> */
 #ifdef HAVE_CURSES_WCHGAT
@@ -1332,15 +1340,13 @@ _curses_window_echochar_impl(PyCursesWindowObject *self, PyObject *ch,
     if (!PyCurses_ConvertToChtype(self, ch, &ch_))
         return NULL;
 
-#ifdef py_is_pad
     if (py_is_pad(self->win)) {
         return PyCursesCheckERR(pechochar(self->win, ch_ | (attr_t)attr),
                                 "echochar");
-    }
-    else
-#endif
+    } else {
         return PyCursesCheckERR(wechochar(self->win, ch_ | (attr_t)attr),
                                 "echochar");
+    }
 }
 
 #ifdef NCURSES_MOUSE_VERSION
@@ -1975,7 +1981,6 @@ _curses_window_is_linetouched_impl(PyCursesWindowObject *self, int line)
     return PyBool_FromLong(erg);
 }
 
-#ifdef py_is_pad
 /*[clinic input]
 _curses.window.noutrefresh
 
@@ -2002,25 +2007,9 @@ _curses_window_noutrefresh_impl(PyCursesWindowObject *self,
                                 int sminrow, int smincol, int smaxrow,
                                 int smaxcol)
 /*[clinic end generated code: output=809a1f3c6a03e23e input=3e56898388cd739e]*/
-#else
-/*[clinic input]
-_curses.window.noutrefresh
-
-Mark for refresh but wait.
-
-This function updates the data structure representing the desired state of the
-window, but does not force an update of the physical screen.  To accomplish
-that, call doupdate().
-[clinic start generated code]*/
-
-static PyObject *
-_curses_window_noutrefresh_impl(PyCursesWindowObject *self)
-/*[clinic end generated code: output=6ef6dec666643fee input=876902e3fa431dbd]*/
-#endif
 {
     int rtn;
 
-#ifdef py_is_pad
     if (py_is_pad(self->win)) {
         if (!group_right_1) {
             PyErr_SetString(PyCursesError,
@@ -2039,7 +2028,6 @@ _curses_window_noutrefresh_impl(PyCursesWindowObject *self)
                         "noutrefresh() takes no arguments (6 given)");
         return NULL;
     }
-#endif
     Py_BEGIN_ALLOW_THREADS
     rtn = wnoutrefresh(self->win);
     Py_END_ALLOW_THREADS
@@ -2244,7 +2232,6 @@ _curses_window_refresh_impl(PyCursesWindowObject *self, int group_right_1,
 {
     int rtn;
 
-#ifdef py_is_pad
     if (py_is_pad(self->win)) {
         if (!group_right_1) {
             PyErr_SetString(PyCursesError,
@@ -2257,7 +2244,6 @@ _curses_window_refresh_impl(PyCursesWindowObject *self, int group_right_1,
         Py_END_ALLOW_THREADS
         return PyCursesCheckERR(rtn, "prefresh");
     }
-#endif
     if (group_right_1) {
         PyErr_SetString(PyExc_TypeError,
                         "refresh() takes no arguments (6 given)");
@@ -2320,13 +2306,11 @@ _curses_window_subwin_impl(PyCursesWindowObject *self, int group_left_1,
     WINDOW *win;
 
     /* printf("Subwin: %i %i %i %i   \n", nlines, ncols, begin_y, begin_x); */
-#ifdef py_is_pad
     if (py_is_pad(self->win)) {
         win = subpad(self->win, nlines, ncols, begin_y, begin_x);
-    }
-    else
-#endif
+    } else {
         win = subwin(self->win, nlines, ncols, begin_y, begin_x);
+    }
 
     if (win == NULL) {
         PyErr_SetString(PyCursesError, catchall_NULL);
@@ -4586,17 +4570,24 @@ make_ncurses_version(PyTypeObject *type)
     if (ncurses_version == NULL) {
         return NULL;
     }
-
+    const char *str = curses_version();
+    unsigned long major = 0, minor = 0, patch = 0;
+    if (!str || sscanf(str, "%*[^0-9]%lu.%lu.%lu", &major, &minor, &patch) < 3) {
+        // Fallback to header version, which cannot be that wrong
+        major = NCURSES_VERSION_MAJOR;
+        minor = NCURSES_VERSION_MINOR;
+        patch = NCURSES_VERSION_PATCH;
+    }
 #define SetIntItem(flag) \
     PyStructSequence_SET_ITEM(ncurses_version, pos++, PyLong_FromLong(flag)); \
     if (PyErr_Occurred()) { \
         Py_CLEAR(ncurses_version); \
         return NULL; \
     }
 
-    SetIntItem(NCURSES_VERSION_MAJOR)
-    SetIntItem(NCURSES_VERSION_MINOR)
-    SetIntItem(NCURSES_VERSION_PATCH)
+    SetIntItem(major)
+    SetIntItem(minor)
+    SetIntItem(patch)
 #undef SetIntItem
 
     return ncurses_version;

configure.ac

@@ -6492,7 +6492,10 @@ AC_DEFUN([PY_CHECK_CURSES_FUNC],
     [py_var],
     [AC_COMPILE_IFELSE(
       [AC_LANG_PROGRAM(
-        [@%:@include <curses.h>], [
+        [[
+        #define NCURSES_OPAQUE 0
+        #include <curses.h>
+        ]], [
         #ifndef $1
         void *x=$1
         #endif