[3.13] gh-152502: Detect optional curses functions with configure probes (GH-152504) (GH-152589) (GH-152602)

set_escdelay(), set_tabsize() and the ESCDELAY and TABSIZE variables were
gated only by the ncurses-specific NCURSES_EXT_FUNCS macro, which excluded
them when building against other curses implementations such as NetBSD curses
even when they provided them.  Detect each with a configure capability probe
and gate on HAVE_CURSES_*.
(cherry picked from commit 0635e55)
(cherry picked from commit 2a4ffa6)

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: serhiy-storchaka

Misc/NEWS.d/next/Build/2026-06-28-16-17-55.gh-issue-152502.6SNqMg.rst

@@ -0,0 +1,5 @@
+The :mod:`curses` module now detects ``set_escdelay()``, ``set_tabsize()`` and
+the ``ESCDELAY`` and ``TABSIZE`` variables with :program:`configure` capability
+probes instead of the ncurses-specific ``NCURSES_EXT_FUNCS`` macro, so they are
+exposed when building against other curses implementations such as NetBSD curses
+that provide them.

Modules/_cursesmodule.c

@@ -3479,9 +3479,7 @@ _curses_setupterm_impl(PyObject *module, const char *term, int fd)
     Py_RETURN_NONE;
 }
 
-#if defined(NCURSES_EXT_FUNCS) && NCURSES_EXT_FUNCS >= 20081102
-// https://invisible-island.net/ncurses/NEWS.html#index-t20080119
-
+#ifdef HAVE_CURSES_ESCDELAY
 /*[clinic input]
 _curses.get_escdelay
 
@@ -3498,6 +3496,9 @@ _curses_get_escdelay_impl(PyObject *module)
 {
     return PyLong_FromLong(ESCDELAY);
 }
+#endif /* HAVE_CURSES_ESCDELAY */
+
+#ifdef HAVE_CURSES_SET_ESCDELAY
 /*[clinic input]
 _curses.set_escdelay
     ms: int
@@ -3522,7 +3523,9 @@ _curses_set_escdelay_impl(PyObject *module, int ms)
 
     return PyCursesCheckERR(set_escdelay(ms), "set_escdelay");
 }
+#endif /* HAVE_CURSES_SET_ESCDELAY */
 
+#ifdef HAVE_CURSES_TABSIZE
 /*[clinic input]
 _curses.get_tabsize
 
@@ -3538,6 +3541,9 @@ _curses_get_tabsize_impl(PyObject *module)
 {
     return PyLong_FromLong(TABSIZE);
 }
+#endif /* HAVE_CURSES_TABSIZE */
+
+#ifdef HAVE_CURSES_SET_TABSIZE
 /*[clinic input]
 _curses.set_tabsize
     size: int
@@ -3561,7 +3567,7 @@ _curses_set_tabsize_impl(PyObject *module, int size)
 
     return PyCursesCheckERR(set_tabsize(size), "set_tabsize");
 }
-#endif
+#endif /* HAVE_CURSES_SET_TABSIZE */
 
 /*[clinic input]
 _curses.intrflush
@@ -4766,10 +4772,8 @@ static PyMethodDef PyCurses_methods[] = {
     _CURSES_RESIZETERM_METHODDEF
     _CURSES_RESIZE_TERM_METHODDEF
     _CURSES_SAVETTY_METHODDEF
-#if defined(NCURSES_EXT_FUNCS) && NCURSES_EXT_FUNCS >= 20081102
     _CURSES_GET_ESCDELAY_METHODDEF
     _CURSES_SET_ESCDELAY_METHODDEF
-#endif
     _CURSES_GET_TABSIZE_METHODDEF
     _CURSES_SET_TABSIZE_METHODDEF
     _CURSES_SETSYX_METHODDEF