gh-113565: Improve and harden detection of curses dependencies (#119816)

1. Use pkg-config to check for ncursesw/panelw. If that fails, use 
   pkg-config to check for ncurses/panel.
2. Regardless of pkg-config output, search for curses/panel headers, so
   we're sure we have all defines in pyconfig.h.
3. Regardless of pkg-config output, check if libncurses or libncursesw
   contains the 'initscr' symbol; if it does _and_ pkg-config failed
   earlier, add the resulting -llib linker option to CURSES_LIBS.
   Ditto for 'update_panels' and PANEL_LIBS.
4. Wrap the rest of the checks with WITH_SAVE_ENV and make sure we're 
   using updated LIBS and CPPFLAGS for those.

Add the PY_CHECK_CURSES convenience macro.

7 files changed, 550 insertions, 716 deletions

diff --git a/Include/py_curses.h b/Include/py_curses.h
index a51d998..79b1b01 100644
--- a/Include/py_curses.h
+++ b/Include/py_curses.h
@@ -36,13 +36,21 @@
 #define NCURSES_OPAQUE 0
 #endif
 
-#ifdef HAVE_NCURSES_H
-#include <ncurses.h>
-#else
-#include <curses.h>
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
 #endif
 
-#ifdef HAVE_NCURSES_H
+#ifdef NCURSES_VERSION
 /* configure was checking <curses.h>, but we will
    use <ncurses.h>, which has some or all these features. */
 #if !defined(WINDOW_HAS_FLAGS) && \
diff --git a/Misc/NEWS.d/next/Build/2024-06-02-13-23-26.gh-issue-113565.8xBlId.rst b/Misc/NEWS.d/next/Build/2024-06-02-13-23-26.gh-issue-113565.8xBlId.rst
new file mode 100644
index 0000000..e26509c
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2024-06-02-13-23-26.gh-issue-113565.8xBlId.rst
@@ -0,0 +1,2 @@
+Improve :mod:`curses` and :mod:`curses.panel` dependency checks in
+:program:`configure`.
diff --git a/Modules/_curses_panel.c b/Modules/_curses_panel.c
index 125c72d..bbbb62c 100644
--- a/Modules/_curses_panel.c
+++ b/Modules/_curses_panel.c
@@ -19,7 +19,13 @@ static const char PyCursesVersion[] = "2.1";
 
 #include "py_curses.h"
 
-#include <panel.h>
+#if defined(HAVE_NCURSESW_PANEL_H)
+#  include <ncursesw/panel.h>
+#elif defined(HAVE_NCURSES_PANEL_H)
+#  include <ncurses/panel.h>
+#elif defined(HAVE_PANEL_H)
+#  include <panel.h>
+#endif
 
 typedef struct {
     PyObject *PyCursesError;
diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
index 3a01196..b5854e8 100644
--- a/Modules/_cursesmodule.c
+++ b/Modules/_cursesmodule.c
@@ -128,7 +128,7 @@ static const char PyCursesVersion[] = "2.2";
 #include <langinfo.h>
 #endif
 
-#if !defined(HAVE_NCURSES_H) && (defined(sgi) || defined(__sun) || defined(SCO5))
+#if !defined(NCURSES_VERSION) && (defined(sgi) || defined(__sun) || defined(SCO5))
 #define STRICT_SYSV_CURSES       /* Don't use ncurses extensions */
 typedef chtype attr_t;           /* No attr_t type is available */
 #endif
diff --git a/configure b/configure
index 99d8643..963ceb9 100755
--- a/configure
+++ b/configure
@@ -26081,25 +26081,11 @@ have_curses=no
 have_panel=no
 
 
-ac_fn_c_check_header_compile "$LINENO" "curses.h" "ac_cv_header_curses_h" "$ac_includes_default"
-if test "x$ac_cv_header_curses_h" = xyes
-then :
-  printf "%s\n" "#define HAVE_CURSES_H 1" >>confdefs.h
 
-fi
-ac_fn_c_check_header_compile "$LINENO" "ncurses.h" "ac_cv_header_ncurses_h" "$ac_includes_default"
-if test "x$ac_cv_header_ncurses_h" = xyes
-then :
-  printf "%s\n" "#define HAVE_NCURSES_H 1" >>confdefs.h
+# Check for ncursesw/panelw first. If that fails, try ncurses/panel.
 
-fi
 
 
-if test "x$ac_cv_header_ncurses_h" = xyes
-then :
-
-  if test "$ac_sys_system" != "Darwin"; then
-
 pkg_failed=no
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for ncursesw" >&5
 printf %s "checking for ncursesw... " >&6; }
@@ -26158,162 +26144,35 @@ fi
 	# Put the nasty error message in config.log where it belongs
 	echo "$CURSES_PKG_ERRORS" >&5
 
-
-      save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for initscr in -lncursesw" >&5
-printf %s "checking for initscr in -lncursesw... " >&6; }
-if test ${ac_cv_lib_ncursesw_initscr+y}
-then :
-  printf %s "(cached) " >&6
-else $as_nop
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lncursesw  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-char initscr ();
-int
-main (void)
-{
-return initscr ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"
-then :
-  ac_cv_lib_ncursesw_initscr=yes
-else $as_nop
-  ac_cv_lib_ncursesw_initscr=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_ncursesw_initscr" >&5
-printf "%s\n" "$ac_cv_lib_ncursesw_initscr" >&6; }
-if test "x$ac_cv_lib_ncursesw_initscr" = xyes
-then :
-
-          printf "%s\n" "#define HAVE_NCURSESW 1" >>confdefs.h
-
-          have_curses=ncursesw
-          CURSES_CFLAGS=${CURSES_CFLAGS-""}
-          CURSES_LIBS=${CURSES_LIBS-"-lncursesw"}
-
-fi
-
-
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
-
+	have_curses=no
 elif test $pkg_failed = untried; then
         { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
 printf "%s\n" "no" >&6; }
-
-      save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for initscr in -lncursesw" >&5
-printf %s "checking for initscr in -lncursesw... " >&6; }
-if test ${ac_cv_lib_ncursesw_initscr+y}
-then :
-  printf %s "(cached) " >&6
-else $as_nop
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lncursesw  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-char initscr ();
-int
-main (void)
-{
-return initscr ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"
-then :
-  ac_cv_lib_ncursesw_initscr=yes
-else $as_nop
-  ac_cv_lib_ncursesw_initscr=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_ncursesw_initscr" >&5
-printf "%s\n" "$ac_cv_lib_ncursesw_initscr" >&6; }
-if test "x$ac_cv_lib_ncursesw_initscr" = xyes
-then :
-
-          printf "%s\n" "#define HAVE_NCURSESW 1" >>confdefs.h
-
-          have_curses=ncursesw
-          CURSES_CFLAGS=${CURSES_CFLAGS-""}
-          CURSES_LIBS=${CURSES_LIBS-"-lncursesw"}
-
-fi
-
-
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
-
+	have_curses=no
 else
 	CURSES_CFLAGS=$pkg_cv_CURSES_CFLAGS
 	CURSES_LIBS=$pkg_cv_CURSES_LIBS
         { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 printf "%s\n" "yes" >&6; }
 
-      printf "%s\n" "#define HAVE_NCURSESW 1" >>confdefs.h
-
-      have_curses=ncursesw
-
-fi
-  fi
-
-  if test "x$have_curses" = xno
-then :
+printf "%s\n" "#define HAVE_NCURSESW 1" >>confdefs.h
 
+   have_curses=yes
 
 pkg_failed=no
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for ncurses" >&5
-printf %s "checking for ncurses... " >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for panelw" >&5
+printf %s "checking for panelw... " >&6; }
 
-if test -n "$CURSES_CFLAGS"; then
-    pkg_cv_CURSES_CFLAGS="$CURSES_CFLAGS"
+if test -n "$PANEL_CFLAGS"; then
+    pkg_cv_PANEL_CFLAGS="$PANEL_CFLAGS"
  elif test -n "$PKG_CONFIG"; then
     if test -n "$PKG_CONFIG" && \
-    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"ncurses\""; } >&5
-  ($PKG_CONFIG --exists --print-errors "ncurses") 2>&5
+    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"panelw\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "panelw") 2>&5
   ac_status=$?
   printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }; then
-  pkg_cv_CURSES_CFLAGS=`$PKG_CONFIG --cflags "ncurses" 2>/dev/null`
+  pkg_cv_PANEL_CFLAGS=`$PKG_CONFIG --cflags "panelw" 2>/dev/null`
 		      test "x$?" != "x0" && pkg_failed=yes
 else
   pkg_failed=yes
@@ -26321,16 +26180,16 @@ fi
  else
     pkg_failed=untried
 fi
-if test -n "$CURSES_LIBS"; then
-    pkg_cv_CURSES_LIBS="$CURSES_LIBS"
+if test -n "$PANEL_LIBS"; then
+    pkg_cv_PANEL_LIBS="$PANEL_LIBS"
  elif test -n "$PKG_CONFIG"; then
     if test -n "$PKG_CONFIG" && \
-    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"ncurses\""; } >&5
-  ($PKG_CONFIG --exists --print-errors "ncurses") 2>&5
+    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"panelw\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "panelw") 2>&5
   ac_status=$?
   printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }; then
-  pkg_cv_CURSES_LIBS=`$PKG_CONFIG --libs "ncurses" 2>/dev/null`
+  pkg_cv_PANEL_LIBS=`$PKG_CONFIG --libs "panelw" 2>/dev/null`
 		      test "x$?" != "x0" && pkg_failed=yes
 else
   pkg_failed=yes
@@ -26351,204 +26210,50 @@ else
         _pkg_short_errors_supported=no
 fi
         if test $_pkg_short_errors_supported = yes; then
-	        CURSES_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "ncurses" 2>&1`
+	        PANEL_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "panelw" 2>&1`
         else
-	        CURSES_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "ncurses" 2>&1`
+	        PANEL_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "panelw" 2>&1`
         fi
 	# Put the nasty error message in config.log where it belongs
-	echo "$CURSES_PKG_ERRORS" >&5
-
-
-      save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for initscr in -lncurses" >&5
-printf %s "checking for initscr in -lncurses... " >&6; }
-if test ${ac_cv_lib_ncurses_initscr+y}
-then :
-  printf %s "(cached) " >&6
-else $as_nop
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lncurses  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-char initscr ();
-int
-main (void)
-{
-return initscr ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"
-then :
-  ac_cv_lib_ncurses_initscr=yes
-else $as_nop
-  ac_cv_lib_ncurses_initscr=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_ncurses_initscr" >&5
-printf "%s\n" "$ac_cv_lib_ncurses_initscr" >&6; }
-if test "x$ac_cv_lib_ncurses_initscr" = xyes
-then :
-
-          have_curses=ncurses
-          CURSES_CFLAGS=${CURSES_CFLAGS-""}
-          CURSES_LIBS=${CURSES_LIBS-"-lncurses"}
-
-fi
-
-
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
+	echo "$PANEL_PKG_ERRORS" >&5
 
+	have_panel=no
 elif test $pkg_failed = untried; then
         { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
 printf "%s\n" "no" >&6; }
-
-      save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for initscr in -lncurses" >&5
-printf %s "checking for initscr in -lncurses... " >&6; }
-if test ${ac_cv_lib_ncurses_initscr+y}
-then :
-  printf %s "(cached) " >&6
-else $as_nop
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lncurses  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-char initscr ();
-int
-main (void)
-{
-return initscr ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"
-then :
-  ac_cv_lib_ncurses_initscr=yes
-else $as_nop
-  ac_cv_lib_ncurses_initscr=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_ncurses_initscr" >&5
-printf "%s\n" "$ac_cv_lib_ncurses_initscr" >&6; }
-if test "x$ac_cv_lib_ncurses_initscr" = xyes
-then :
-
-          have_curses=ncurses
-          CURSES_CFLAGS=${CURSES_CFLAGS-""}
-          CURSES_LIBS=${CURSES_LIBS-"-lncurses"}
-
-fi
-
-
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
-
+	have_panel=no
 else
-	CURSES_CFLAGS=$pkg_cv_CURSES_CFLAGS
-	CURSES_LIBS=$pkg_cv_CURSES_LIBS
+	PANEL_CFLAGS=$pkg_cv_PANEL_CFLAGS
+	PANEL_LIBS=$pkg_cv_PANEL_LIBS
         { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 printf "%s\n" "yes" >&6; }
 
-      have_curses=ncurses
-
-fi
+printf "%s\n" "#define HAVE_PANELW 1" >>confdefs.h
 
+     have_panel=yes
 fi
-
-
-fi
-CURSES_CFLAGS=$(echo $CURSES_CFLAGS | sed 's/-D_XOPEN_SOURCE=600//g')
-
-if test "$have_curses" != no -a "$ac_sys_system" = "Darwin"; then
-
-  as_fn_append CURSES_CFLAGS " -D_XOPEN_SOURCE_EXTENDED=1"
-  printf "%s\n" "#define HAVE_NCURSESW 1" >>confdefs.h
-
 fi
 
 
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking curses module flags" >&5
-printf %s "checking curses module flags... " >&6; }
 if test "x$have_curses" = xno
 then :
 
-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
-printf "%s\n" "no" >&6; }
-
-else $as_nop
-
-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $have_curses (CFLAGS: $CURSES_CFLAGS, LIBS: $CURSES_LIBS)" >&5
-printf "%s\n" "$have_curses (CFLAGS: $CURSES_CFLAGS, LIBS: $CURSES_LIBS)" >&6; }
-
-fi
-
-ac_fn_c_check_header_compile "$LINENO" "panel.h" "ac_cv_header_panel_h" "$ac_includes_default"
-if test "x$ac_cv_header_panel_h" = xyes
-then :
-  printf "%s\n" "#define HAVE_PANEL_H 1" >>confdefs.h
-
-fi
-
-
-if test "x$ac_cv_header_panel_h" = xyes
-then :
-
-
-  if test "$ac_sys_system" != "Darwin"; then
-        if test "x$have_curses" = xncursesw
-then :
 
 
 pkg_failed=no
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for panelw" >&5
-printf %s "checking for panelw... " >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for ncurses" >&5
+printf %s "checking for ncurses... " >&6; }
 
-if test -n "$PANEL_CFLAGS"; then
-    pkg_cv_PANEL_CFLAGS="$PANEL_CFLAGS"
+if test -n "$CURSES_CFLAGS"; then
+    pkg_cv_CURSES_CFLAGS="$CURSES_CFLAGS"
  elif test -n "$PKG_CONFIG"; then
     if test -n "$PKG_CONFIG" && \
-    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"panelw\""; } >&5
-  ($PKG_CONFIG --exists --print-errors "panelw") 2>&5
+    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"ncurses\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "ncurses") 2>&5
   ac_status=$?
   printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }; then
-  pkg_cv_PANEL_CFLAGS=`$PKG_CONFIG --cflags "panelw" 2>/dev/null`
+  pkg_cv_CURSES_CFLAGS=`$PKG_CONFIG --cflags "ncurses" 2>/dev/null`
 		      test "x$?" != "x0" && pkg_failed=yes
 else
   pkg_failed=yes
@@ -26556,16 +26261,16 @@ fi
  else
     pkg_failed=untried
 fi
-if test -n "$PANEL_LIBS"; then
-    pkg_cv_PANEL_LIBS="$PANEL_LIBS"
+if test -n "$CURSES_LIBS"; then
+    pkg_cv_CURSES_LIBS="$CURSES_LIBS"
  elif test -n "$PKG_CONFIG"; then
     if test -n "$PKG_CONFIG" && \
-    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"panelw\""; } >&5
-  ($PKG_CONFIG --exists --print-errors "panelw") 2>&5
+    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"ncurses\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "ncurses") 2>&5
   ac_status=$?
   printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }; then
-  pkg_cv_PANEL_LIBS=`$PKG_CONFIG --libs "panelw" 2>/dev/null`
+  pkg_cv_CURSES_LIBS=`$PKG_CONFIG --libs "ncurses" 2>/dev/null`
 		      test "x$?" != "x0" && pkg_failed=yes
 else
   pkg_failed=yes
@@ -26586,150 +26291,27 @@ else
         _pkg_short_errors_supported=no
 fi
         if test $_pkg_short_errors_supported = yes; then
-	        PANEL_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "panelw" 2>&1`
+	        CURSES_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "ncurses" 2>&1`
         else
-	        PANEL_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "panelw" 2>&1`
+	        CURSES_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "ncurses" 2>&1`
         fi
 	# Put the nasty error message in config.log where it belongs
-	echo "$PANEL_PKG_ERRORS" >&5
-
-
-        save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for update_panels in -lpanelw" >&5
-printf %s "checking for update_panels in -lpanelw... " >&6; }
-if test ${ac_cv_lib_panelw_update_panels+y}
-then :
-  printf %s "(cached) " >&6
-else $as_nop
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lpanelw  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-char update_panels ();
-int
-main (void)
-{
-return update_panels ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"
-then :
-  ac_cv_lib_panelw_update_panels=yes
-else $as_nop
-  ac_cv_lib_panelw_update_panels=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_panelw_update_panels" >&5
-printf "%s\n" "$ac_cv_lib_panelw_update_panels" >&6; }
-if test "x$ac_cv_lib_panelw_update_panels" = xyes
-then :
-
-            have_panel=panelw
-            PANEL_CFLAGS=${PANEL_CFLAGS-""}
-            PANEL_LIBS=${PANEL_LIBS-"-lpanelw"}
-
-fi
-
-
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
+	echo "$CURSES_PKG_ERRORS" >&5
 
+	have_curses=no
 elif test $pkg_failed = untried; then
         { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
 printf "%s\n" "no" >&6; }
-
-        save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-          { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for update_panels in -lpanelw" >&5
-printf %s "checking for update_panels in -lpanelw... " >&6; }
-if test ${ac_cv_lib_panelw_update_panels+y}
-then :
-  printf %s "(cached) " >&6
-else $as_nop
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lpanelw  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-char update_panels ();
-int
-main (void)
-{
-return update_panels ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"
-then :
-  ac_cv_lib_panelw_update_panels=yes
-else $as_nop
-  ac_cv_lib_panelw_update_panels=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_panelw_update_panels" >&5
-printf "%s\n" "$ac_cv_lib_panelw_update_panels" >&6; }
-if test "x$ac_cv_lib_panelw_update_panels" = xyes
-then :
-
-            have_panel=panelw
-            PANEL_CFLAGS=${PANEL_CFLAGS-""}
-            PANEL_LIBS=${PANEL_LIBS-"-lpanelw"}
-
-fi
-
-
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
-
+	have_curses=no
 else
-	PANEL_CFLAGS=$pkg_cv_PANEL_CFLAGS
-	PANEL_LIBS=$pkg_cv_PANEL_LIBS
+	CURSES_CFLAGS=$pkg_cv_CURSES_CFLAGS
+	CURSES_LIBS=$pkg_cv_CURSES_LIBS
         { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 printf "%s\n" "yes" >&6; }
 
-        have_panel=panelw
-
-fi
-
-fi
-  fi
-
-  if test "x$have_curses" = xncurses
-then :
+printf "%s\n" "#define HAVE_NCURSES 1" >>confdefs.h
 
+   have_curses=yes
 
 pkg_failed=no
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for panel" >&5
@@ -26789,83 +26371,165 @@ fi
 	# Put the nasty error message in config.log where it belongs
 	echo "$PANEL_PKG_ERRORS" >&5
 
+	have_panel=no
+elif test $pkg_failed = untried; then
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+	have_panel=no
+else
+	PANEL_CFLAGS=$pkg_cv_PANEL_CFLAGS
+	PANEL_LIBS=$pkg_cv_PANEL_LIBS
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+
+printf "%s\n" "#define HAVE_PANEL 1" >>confdefs.h
 
-      save_CFLAGS=$CFLAGS
+     have_panel=yes
+fi
+fi
+
+
+fi
+
+save_CFLAGS=$CFLAGS
 save_CPPFLAGS=$CPPFLAGS
 save_LDFLAGS=$LDFLAGS
 save_LIBS=$LIBS
 
 
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for update_panels in -lpanel" >&5
-printf %s "checking for update_panels in -lpanel... " >&6; }
-if test ${ac_cv_lib_panel_update_panels+y}
+  # Make sure we've got the header defines.
+  as_fn_append CPPFLAGS " $CURSES_CFLAGS $PANEL_CFLAGS"
+  ac_fn_c_check_header_compile "$LINENO" "ncursesw/curses.h" "ac_cv_header_ncursesw_curses_h" "$ac_includes_default"
+if test "x$ac_cv_header_ncursesw_curses_h" = xyes
+then :
+  printf "%s\n" "#define HAVE_NCURSESW_CURSES_H 1" >>confdefs.h
+
+fi
+ac_fn_c_check_header_compile "$LINENO" "ncursesw/ncurses.h" "ac_cv_header_ncursesw_ncurses_h" "$ac_includes_default"
+if test "x$ac_cv_header_ncursesw_ncurses_h" = xyes
+then :
+  printf "%s\n" "#define HAVE_NCURSESW_NCURSES_H 1" >>confdefs.h
+
+fi
+ac_fn_c_check_header_compile "$LINENO" "ncursesw/panel.h" "ac_cv_header_ncursesw_panel_h" "$ac_includes_default"
+if test "x$ac_cv_header_ncursesw_panel_h" = xyes
+then :
+  printf "%s\n" "#define HAVE_NCURSESW_PANEL_H 1" >>confdefs.h
+
+fi
+ac_fn_c_check_header_compile "$LINENO" "ncurses/curses.h" "ac_cv_header_ncurses_curses_h" "$ac_includes_default"
+if test "x$ac_cv_header_ncurses_curses_h" = xyes
+then :
+  printf "%s\n" "#define HAVE_NCURSES_CURSES_H 1" >>confdefs.h
+
+fi
+ac_fn_c_check_header_compile "$LINENO" "ncurses/ncurses.h" "ac_cv_header_ncurses_ncurses_h" "$ac_includes_default"
+if test "x$ac_cv_header_ncurses_ncurses_h" = xyes
+then :
+  printf "%s\n" "#define HAVE_NCURSES_NCURSES_H 1" >>confdefs.h
+
+fi
+ac_fn_c_check_header_compile "$LINENO" "ncurses/panel.h" "ac_cv_header_ncurses_panel_h" "$ac_includes_default"
+if test "x$ac_cv_header_ncurses_panel_h" = xyes
+then :
+  printf "%s\n" "#define HAVE_NCURSES_PANEL_H 1" >>confdefs.h
+
+fi
+ac_fn_c_check_header_compile "$LINENO" "curses.h" "ac_cv_header_curses_h" "$ac_includes_default"
+if test "x$ac_cv_header_curses_h" = xyes
+then :
+  printf "%s\n" "#define HAVE_CURSES_H 1" >>confdefs.h
+
+fi
+ac_fn_c_check_header_compile "$LINENO" "ncurses.h" "ac_cv_header_ncurses_h" "$ac_includes_default"
+if test "x$ac_cv_header_ncurses_h" = xyes
+then :
+  printf "%s\n" "#define HAVE_NCURSES_H 1" >>confdefs.h
+
+fi
+ac_fn_c_check_header_compile "$LINENO" "panel.h" "ac_cv_header_panel_h" "$ac_includes_default"
+if test "x$ac_cv_header_panel_h" = xyes
+then :
+  printf "%s\n" "#define HAVE_PANEL_H 1" >>confdefs.h
+
+fi
+
+
+  # Check that we're able to link with crucial curses/panel functions. This
+  # also serves as a fallback in case pkg-config failed.
+  as_fn_append LIBS " $CURSES_LIBS $PANEL_LIBS"
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing initscr" >&5
+printf %s "checking for library containing initscr... " >&6; }
+if test ${ac_cv_search_initscr+y}
 then :
   printf %s "(cached) " >&6
 else $as_nop
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lpanel  $LIBS"
+  ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 /* Override any GCC internal prototype to avoid an error.
    Use char because int might match the return type of a GCC
    builtin and then its argument prototype would still apply.  */
-char update_panels ();
+char initscr ();
 int
 main (void)
 {
-return update_panels ();
+return initscr ();
   ;
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_link "$LINENO"
+for ac_lib in '' ncursesw ncurses
+do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  if ac_fn_c_try_link "$LINENO"
 then :
-  ac_cv_lib_panel_update_panels=yes
-else $as_nop
-  ac_cv_lib_panel_update_panels=no
+  ac_cv_search_initscr=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.beam \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
+    conftest$ac_exeext
+  if test ${ac_cv_search_initscr+y}
+then :
+  break
 fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_panel_update_panels" >&5
-printf "%s\n" "$ac_cv_lib_panel_update_panels" >&6; }
-if test "x$ac_cv_lib_panel_update_panels" = xyes
+done
+if test ${ac_cv_search_initscr+y}
 then :
 
-          have_panel=panel
-          PANEL_CFLAGS=${PANEL_CFLAGS-""}
-          PANEL_LIBS=${PANEL_LIBS-"-lpanel"}
-
+else $as_nop
+  ac_cv_search_initscr=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_initscr" >&5
+printf "%s\n" "$ac_cv_search_initscr" >&6; }
+ac_res=$ac_cv_search_initscr
+if test "$ac_res" != no
+then :
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+  if test "x$have_curses" = xno
+then :
+  have_curses=yes
+       CURSES_LIBS=${CURSES_LIBS-"$ac_cv_search_initscr"}
+fi
+else $as_nop
+  have_curses=no
 fi
 
-
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
-
-elif test $pkg_failed = untried; then
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
-printf "%s\n" "no" >&6; }
-
-      save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for update_panels in -lpanel" >&5
-printf %s "checking for update_panels in -lpanel... " >&6; }
-if test ${ac_cv_lib_panel_update_panels+y}
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing update_panels" >&5
+printf %s "checking for library containing update_panels... " >&6; }
+if test ${ac_cv_search_update_panels+y}
 then :
   printf %s "(cached) " >&6
 else $as_nop
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lpanel  $LIBS"
+  ac_func_search_save_LIBS=$LIBS
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -26881,76 +26545,82 @@ return update_panels ();
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_link "$LINENO"
+for ac_lib in '' panelw panel
+do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  if ac_fn_c_try_link "$LINENO"
 then :
-  ac_cv_lib_panel_update_panels=yes
-else $as_nop
-  ac_cv_lib_panel_update_panels=no
+  ac_cv_search_update_panels=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.beam \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
+    conftest$ac_exeext
+  if test ${ac_cv_search_update_panels+y}
+then :
+  break
 fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_panel_update_panels" >&5
-printf "%s\n" "$ac_cv_lib_panel_update_panels" >&6; }
-if test "x$ac_cv_lib_panel_update_panels" = xyes
+done
+if test ${ac_cv_search_update_panels+y}
 then :
 
-          have_panel=panel
-          PANEL_CFLAGS=${PANEL_CFLAGS-""}
-          PANEL_LIBS=${PANEL_LIBS-"-lpanel"}
-
+else $as_nop
+  ac_cv_search_update_panels=no
 fi
-
-
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
-
-else
-	PANEL_CFLAGS=$pkg_cv_PANEL_CFLAGS
-	PANEL_LIBS=$pkg_cv_PANEL_LIBS
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-printf "%s\n" "yes" >&6; }
-
-      have_panel=panel
-
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
 fi
-
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_update_panels" >&5
+printf "%s\n" "$ac_cv_search_update_panels" >&6; }
+ac_res=$ac_cv_search_update_panels
+if test "$ac_res" != no
+then :
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+  if test "x$have_panel" = xno
+then :
+  have_panel=yes
+       PANEL_LIBS=${PANEL_LIBS-"$ac_cv_search_update_panels"}
+fi
+else $as_nop
+  have_panel=no
 fi
 
 
-fi
-PANEL_CFLAGS=$(echo $PANEL_CFLAGS | sed 's/-D_XOPEN_SOURCE=600//g')
 
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking panel flags" >&5
-printf %s "checking panel flags... " >&6; }
-if test "x$have_panel" = xno
+
+if test "have_curses" != "no"
 then :
 
-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
-printf "%s\n" "no" >&6; }
+CURSES_CFLAGS=$(echo $CURSES_CFLAGS | sed 's/-D_XOPEN_SOURCE=600//g')
 
-else $as_nop
+if test "x$ac_sys_system" = xDarwin
+then :
 
-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $have_panel (CFLAGS: $PANEL_CFLAGS, LIBS: $PANEL_LIBS)" >&5
-printf "%s\n" "$have_panel (CFLAGS: $PANEL_CFLAGS, LIBS: $PANEL_LIBS)" >&6; }
 
-fi
+  as_fn_append CURSES_CFLAGS " -D_XOPEN_SOURCE_EXTENDED=1"
 
-# first curses header check
-ac_save_cppflags="$CPPFLAGS"
-if test "$cross_compiling" = no; then
-  CPPFLAGS="$CPPFLAGS -I/usr/include/ncursesw"
 fi
 
+PANEL_CFLAGS=$(echo $PANEL_CFLAGS | sed 's/-D_XOPEN_SOURCE=600//g')
+
 # On Solaris, term.h requires curses.h
 ac_fn_c_check_header_compile "$LINENO" "term.h" "ac_cv_header_term_h" "
-#ifdef HAVE_CURSES_H
-#include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
 #endif
 
 "
@@ -26970,7 +26640,22 @@ then :
 else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-#include <curses.h>
+
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
+
 int
 main (void)
 {
@@ -27000,10 +26685,6 @@ printf "%s\n" "#define MVWDELCH_IS_EXPRESSION 1" >>confdefs.h
 
 fi
 
-# Issue #25720: ncurses has introduced the NCURSES_OPAQUE symbol making opaque
-# structs since version 5.7.  If the macro is defined as zero before including
-# [n]curses.h, ncurses will expose fields of the structs regardless of the
-# configuration.
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether WINDOW has _flags" >&5
 printf %s "checking whether WINDOW has _flags... " >&6; }
 if test ${ac_cv_window_has_flags+y}
@@ -27013,8 +26694,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-  #define NCURSES_OPAQUE 0
-  #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27059,8 +26752,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27105,8 +26810,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27151,8 +26868,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27197,8 +26926,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27243,8 +26984,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27289,8 +27042,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27335,8 +27100,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27381,8 +27158,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27427,8 +27216,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27473,8 +27274,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27519,8 +27332,20 @@ else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
 
 int
 main (void)
@@ -27556,6 +27381,13 @@ fi
 
 CPPFLAGS=$ac_save_cppflags
 
+fi
+CFLAGS=$save_CFLAGS
+CPPFLAGS=$save_CPPFLAGS
+LDFLAGS=$save_LDFLAGS
+LIBS=$save_LIBS
+
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for device files" >&5
 printf "%s\n" "$as_me: checking for device files" >&6;}
 
@@ -30625,7 +30457,7 @@ then :
 
     if true
 then :
-  if test "$have_curses" != "no"
+  if test "$have_curses" = "yes"
 then :
   py_cv_module__curses=yes
 else $as_nop
@@ -30664,7 +30496,7 @@ then :
 
     if true
 then :
-  if test "$have_panel" != "no"
+  if test "$have_curses" = "yes" && test "$have_panel" = "yes"
 then :
   py_cv_module__curses_panel=yes
 else $as_nop
diff --git a/configure.ac b/configure.ac
index e4f8f41..460dd89 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6663,55 +6663,88 @@ then
   [Define if year with century should be normalized for strftime.])
 fi
 
-dnl check for ncurses/ncursesw and panel/panelw
+dnl check for ncursesw/ncurses and panelw/panel
 dnl NOTE: old curses is not detected.
-dnl have_curses=[no, ncursesw, ncurses]
-dnl have_panel=[no, panelw, panel]
+dnl have_curses=[no, yes]
+dnl have_panel=[no, yes]
 have_curses=no
 have_panel=no
 
-AH_TEMPLATE([HAVE_NCURSESW], [Define to 1 if you have the `ncursesw' library.])
-AC_CHECK_HEADERS([curses.h ncurses.h])
+dnl PY_CHECK_CURSES(LIBCURSES, LIBPANEL)
+dnl Sets 'have_curses' and 'have_panel'.
+dnl For the PKG_CHECK_MODULES() calls, we can safely reuse the first variable
+dnl here, since we're only calling the macro a second time if the first call
+dnl fails.
+AC_DEFUN([PY_CHECK_CURSES], [dnl
+AS_VAR_PUSHDEF([curses_var], [m4_toupper([$1])])
+AS_VAR_PUSHDEF([panel_var], [m4_toupper([$2])])
+PKG_CHECK_MODULES([CURSES], [$1],
+  [AC_DEFINE([HAVE_]curses_var, [1], [Define if you have the '$1' library])
+   AS_VAR_SET([have_curses], [yes])
+   PKG_CHECK_MODULES([PANEL], [$2],
+    [AC_DEFINE([HAVE_]panel_var, [1], [Define if you have the '$2' library])
+     AS_VAR_SET([have_panel], [yes])],
+    [AS_VAR_SET([have_panel], [no])])],
+  [AS_VAR_SET([have_curses], [no])])
+AS_VAR_POPDEF([curses_var])
+AS_VAR_POPDEF([panel_var])])
+
+# Check for ncursesw/panelw first. If that fails, try ncurses/panel.
+PY_CHECK_CURSES([ncursesw], [panelw])
+AS_VAR_IF([have_curses], [no],
+          [PY_CHECK_CURSES([ncurses], [panel])])
 
-AS_VAR_IF([ac_cv_header_ncurses_h], [yes], [
-  if test "$ac_sys_system" != "Darwin"; then
-    dnl On macOS, there is no separate /usr/lib/libncursesw nor libpanelw.
-    PKG_CHECK_MODULES([CURSES], [ncursesw], [
-      AC_DEFINE([HAVE_NCURSESW], [1])
-      have_curses=ncursesw
-    ], [
-      WITH_SAVE_ENV([
-        AC_CHECK_LIB([ncursesw], [initscr], [
-          AC_DEFINE([HAVE_NCURSESW], [1])
-          have_curses=ncursesw
-          CURSES_CFLAGS=${CURSES_CFLAGS-""}
-          CURSES_LIBS=${CURSES_LIBS-"-lncursesw"}
-        ])
-      ])
-    ])
-  fi
-
-  AS_VAR_IF([have_curses], [no], [
-    PKG_CHECK_MODULES([CURSES], [ncurses], [
-      have_curses=ncurses
-    ], [
-      WITH_SAVE_ENV([
-        AC_CHECK_LIB([ncurses], [initscr], [
-          have_curses=ncurses
-          CURSES_CFLAGS=${CURSES_CFLAGS-""}
-          CURSES_LIBS=${CURSES_LIBS-"-lncurses"}
-        ])
-      ])
-    ])
-  ])
+WITH_SAVE_ENV([
+  # Make sure we've got the header defines.
+  AS_VAR_APPEND([CPPFLAGS], [" $CURSES_CFLAGS $PANEL_CFLAGS"])
+  AC_CHECK_HEADERS(m4_normalize([
+    ncursesw/curses.h ncursesw/ncurses.h ncursesw/panel.h
+    ncurses/curses.h ncurses/ncurses.h ncurses/panel.h
+    curses.h ncurses.h panel.h
+  ]))
 
-])dnl ac_cv_header_ncurses_h = yes
+  # Check that we're able to link with crucial curses/panel functions. This
+  # also serves as a fallback in case pkg-config failed.
+  AS_VAR_APPEND([LIBS], [" $CURSES_LIBS $PANEL_LIBS"])
+  AC_SEARCH_LIBS([initscr], [ncursesw ncurses],
+    [AS_VAR_IF([have_curses], [no],
+      [AS_VAR_SET([have_curses], [yes])
+       CURSES_LIBS=${CURSES_LIBS-"$ac_cv_search_initscr"}])],
+    [AS_VAR_SET([have_curses], [no])])
+  AC_SEARCH_LIBS([update_panels], [panelw panel],
+    [AS_VAR_IF([have_panel], [no],
+      [AS_VAR_SET([have_panel], [yes])
+       PANEL_LIBS=${PANEL_LIBS-"$ac_cv_search_update_panels"}])],
+    [AS_VAR_SET([have_panel], [no])])
+
+dnl Issue #25720: ncurses has introduced the NCURSES_OPAQUE symbol making opaque
+dnl structs since version 5.7.  If the macro is defined as zero before including
+dnl [n]curses.h, ncurses will expose fields of the structs regardless of the
+dnl configuration.
+AC_DEFUN([_CURSES_INCLUDES],dnl
+[
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
+])
 
+AS_IF([test "have_curses" != "no"], [
 dnl remove _XOPEN_SOURCE macro from curses cflags. pyconfig.h sets
 dnl the macro to 700.
 CURSES_CFLAGS=$(echo $CURSES_CFLAGS | sed 's/-D_XOPEN_SOURCE=600//g')
 
-if test "$have_curses" != no -a "$ac_sys_system" = "Darwin"; then
+AS_VAR_IF([ac_sys_system], [Darwin], [
   dnl On macOS, there is no separate /usr/lib/libncursesw nor libpanelw.
   dnl System-supplied ncurses combines libncurses/libpanel and supports wide
   dnl characters, so we can use it like ncursesw.
@@ -6721,82 +6754,17 @@ if test "$have_curses" != no -a "$ac_sys_system" = "Darwin"; then
   dnl _XOPEN_SOURCE_EXTENDED here for ncurses wide char support.
 
   AS_VAR_APPEND([CURSES_CFLAGS], [" -D_XOPEN_SOURCE_EXTENDED=1"])
-  AC_DEFINE([HAVE_NCURSESW], [1])
-fi
-
-dnl TODO: detect "curses" and special cases tinfo, terminfo, or termcap
-
-AC_MSG_CHECKING([curses module flags])
-AS_VAR_IF([have_curses], [no], [
-  AC_MSG_RESULT([no])
-], [
-  AC_MSG_RESULT([$have_curses (CFLAGS: $CURSES_CFLAGS, LIBS: $CURSES_LIBS)])
 ])
 
-dnl check for ncurses' panel/panelw library
-AC_CHECK_HEADERS([panel.h])
-
-AS_VAR_IF([ac_cv_header_panel_h], [yes], [
-
-  if test "$ac_sys_system" != "Darwin"; then
-    dnl On macOS, there is no separate /usr/lib/libncursesw nor libpanelw.
-    AS_VAR_IF([have_curses], [ncursesw], [
-      PKG_CHECK_MODULES([PANEL], [panelw], [
-        have_panel=panelw
-      ], [
-        WITH_SAVE_ENV([
-          AC_CHECK_LIB([panelw], [update_panels], [
-            have_panel=panelw
-            PANEL_CFLAGS=${PANEL_CFLAGS-""}
-            PANEL_LIBS=${PANEL_LIBS-"-lpanelw"}
-          ])
-        ])
-      ])
-    ])
-  fi
-
-  AS_VAR_IF([have_curses], [ncurses], [
-    PKG_CHECK_MODULES([PANEL], [panel], [
-      have_panel=panel
-    ], [
-      WITH_SAVE_ENV([
-        AC_CHECK_LIB([panel], [update_panels], [
-          have_panel=panel
-          PANEL_CFLAGS=${PANEL_CFLAGS-""}
-          PANEL_LIBS=${PANEL_LIBS-"-lpanel"}
-        ])
-      ])
-    ])
-  ])
-
-])dnl ac_cv_header_panel_h = yes
-
 dnl pyconfig.h defines _XOPEN_SOURCE=700
 PANEL_CFLAGS=$(echo $PANEL_CFLAGS | sed 's/-D_XOPEN_SOURCE=600//g')
 
-AC_MSG_CHECKING([panel flags])
-AS_VAR_IF([have_panel], [no], [
-  AC_MSG_RESULT([no])
-], [
-  AC_MSG_RESULT([$have_panel (CFLAGS: $PANEL_CFLAGS, LIBS: $PANEL_LIBS)])
-])
-
-# first curses header check
-ac_save_cppflags="$CPPFLAGS"
-if test "$cross_compiling" = no; then
-  CPPFLAGS="$CPPFLAGS -I/usr/include/ncursesw"
-fi
-
 # On Solaris, term.h requires curses.h
-AC_CHECK_HEADERS([term.h], [], [], [
-#ifdef HAVE_CURSES_H
-#include <curses.h>
-#endif
-])
+AC_CHECK_HEADERS([term.h], [], [], _CURSES_INCLUDES)
 
 # On HP/UX 11.0, mvwdelch is a block with a return statement
 AC_CACHE_CHECK([whether mvwdelch is an expression], [ac_cv_mvwdelch_is_expression],
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[@%:@include <curses.h>]], [[
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM(_CURSES_INCLUDES, [[
   int rtn;
   rtn = mvwdelch(0,0,0);
 ]])],
@@ -6809,15 +6777,8 @@ then
   [Define if mvwdelch in curses.h is an expression.])
 fi
 
-# Issue #25720: ncurses has introduced the NCURSES_OPAQUE symbol making opaque
-# structs since version 5.7.  If the macro is defined as zero before including
-# [n]curses.h, ncurses will expose fields of the structs regardless of the
-# configuration.
 AC_CACHE_CHECK([whether WINDOW has _flags], [ac_cv_window_has_flags],
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-  #define NCURSES_OPAQUE 0
-  #include <curses.h>
-]], [[
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM(_CURSES_INCLUDES, [[
   WINDOW *w;
   w->_flags = 0;
 ]])],
@@ -6839,11 +6800,7 @@ AC_DEFUN([PY_CHECK_CURSES_FUNC],
     [for curses function $1],
     [py_var],
     [AC_COMPILE_IFELSE(
-      [AC_LANG_PROGRAM(
-        [
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
-        ], [
+      [AC_LANG_PROGRAM(_CURSES_INCLUDES, [
         #ifndef $1
         void *x=$1
         #endif
@@ -6871,6 +6828,8 @@ PY_CHECK_CURSES_FUNC([has_key])
 PY_CHECK_CURSES_FUNC([typeahead])
 PY_CHECK_CURSES_FUNC([use_env])
 CPPFLAGS=$ac_save_cppflags
+])dnl have_curses != no
+])dnl save env
 
 AC_MSG_NOTICE([checking for device files])
 
@@ -7788,11 +7747,11 @@ PY_STDLIB_MOD([_ctypes],
   [], [test "$have_libffi" = yes],
   [$NO_STRICT_OVERFLOW_CFLAGS $LIBFFI_CFLAGS], [$LIBFFI_LIBS])
 PY_STDLIB_MOD([_curses],
-  [], [test "$have_curses" != "no"],
+  [], [test "$have_curses" = "yes"],
   [$CURSES_CFLAGS], [$CURSES_LIBS]
 )
 PY_STDLIB_MOD([_curses_panel],
-  [], [test "$have_panel" != "no"],
+  [], [test "$have_curses" = "yes" && test "$have_panel" = "yes"],
   [$PANEL_CFLAGS $CURSES_CFLAGS], [$PANEL_LIBS $CURSES_LIBS]
 )
 PY_STDLIB_MOD([_decimal],
diff --git a/pyconfig.h.in b/pyconfig.h.in
index a90f936..10980c9 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -829,12 +829,33 @@
 /* Define to 1 if you have the `nanosleep' function. */
 #undef HAVE_NANOSLEEP
 
-/* Define to 1 if you have the `ncursesw' library. */
+/* Define if you have the 'ncurses' library */
+#undef HAVE_NCURSES
+
+/* Define if you have the 'ncursesw' library */
 #undef HAVE_NCURSESW
 
+/* Define to 1 if you have the <ncursesw/curses.h> header file. */
+#undef HAVE_NCURSESW_CURSES_H
+
+/* Define to 1 if you have the <ncursesw/ncurses.h> header file. */
+#undef HAVE_NCURSESW_NCURSES_H
+
+/* Define to 1 if you have the <ncursesw/panel.h> header file. */
+#undef HAVE_NCURSESW_PANEL_H
+
+/* Define to 1 if you have the <ncurses/curses.h> header file. */
+#undef HAVE_NCURSES_CURSES_H
+
 /* Define to 1 if you have the <ncurses.h> header file. */
 #undef HAVE_NCURSES_H
 
+/* Define to 1 if you have the <ncurses/ncurses.h> header file. */
+#undef HAVE_NCURSES_NCURSES_H
+
+/* Define to 1 if you have the <ncurses/panel.h> header file. */
+#undef HAVE_NCURSES_PANEL_H
+
 /* Define to 1 if you have the <ndbm.h> header file. */
 #undef HAVE_NDBM_H
 
@@ -878,6 +899,12 @@
 /* Define to 1 if you have the `openpty' function. */
 #undef HAVE_OPENPTY
 
+/* Define if you have the 'panel' library */
+#undef HAVE_PANEL
+
+/* Define if you have the 'panelw' library */
+#undef HAVE_PANELW
+
 /* Define to 1 if you have the <panel.h> header file. */
 #undef HAVE_PANEL_H