Fix: handle curses libraries already in LIBS

Author: ashm-dev

Misc/NEWS.d/next/Build/2026-08-20-17-41-11.gh-issue-155911.yL3z8q.rst

@@ -0,0 +1,2 @@
+Fix curses detection with libraries in ``LIBS`` and ``--without-curses``.
+Patched by Shamil Abdulaev.

configure

@@ -7248,8 +7248,8 @@ AS_VAR_POPDEF([panel_var])])
 
 # Detect the selected backend.  ncursesw/ncurses are found via pkg-config;
 # native curses has no .pc file and is left to the header/link probes below.
-# curses_libs/panel_libs drive the AC_SEARCH_LIBS fallback; for "no" they are
-# empty so nothing links and have_curses stays "no".
+# curses_libs/panel_libs drive the AC_SEARCH_LIBS fallback; "no" skips the
+# probes below.
 AS_CASE([$with_curses],
   [ncursesw], [PY_CHECK_CURSES([ncursesw], [panelw])
                curses_libs="ncursesw"; panel_libs="panelw gnupanel"],
@@ -7262,6 +7262,7 @@ AS_CASE([$with_curses],
    AS_VAR_IF([have_curses], [no], [PY_CHECK_CURSES([ncurses], [panel])])
    curses_libs="ncursesw ncurses"; panel_libs="panelw panel gnupanel"])
 
+AS_VAR_IF([with_curses], [no], [], [
 WITH_SAVE_ENV([
   # Make sure we've got the header defines.  For the native "curses" backend,
   # probe only the plain headers: a system may also have ncurses headers (e.g.
@@ -7280,14 +7281,18 @@ WITH_SAVE_ENV([
   # also serves as a fallback in case pkg-config failed.
   AS_VAR_APPEND([LIBS], [" $CURSES_LIBS $PANEL_LIBS"])
   AC_SEARCH_LIBS([initscr], [$curses_libs],
-    [AS_VAR_IF([have_curses], [no],
-      [AS_VAR_SET([have_curses], [yes])
-       CURSES_LIBS=${CURSES_LIBS-"$ac_cv_search_initscr"}])],
+    [AS_VAR_IF([have_curses], [no], [
+      AS_VAR_SET([have_curses], [yes])
+      AS_VAR_IF([ac_cv_search_initscr], ["none required"], [],
+        [CURSES_LIBS=${CURSES_LIBS-"$ac_cv_search_initscr"}])
+    ])],
     [AS_VAR_SET([have_curses], [no])])
   AC_SEARCH_LIBS([update_panels], [$panel_libs],
-    [AS_VAR_IF([have_panel], [no],
-      [AS_VAR_SET([have_panel], [yes])
-       PANEL_LIBS=${PANEL_LIBS-"$ac_cv_search_update_panels"}])],
+    [AS_VAR_IF([have_panel], [no], [
+      AS_VAR_SET([have_panel], [yes])
+      AS_VAR_IF([ac_cv_search_update_panels], ["none required"], [],
+        [PANEL_LIBS=${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
@@ -7498,6 +7503,7 @@ PY_CHECK_CURSES_FUNC([scr_set])
 CPPFLAGS=$ac_save_cppflags
 ])dnl have_curses != no
 ])dnl save env
+])dnl with_curses != no
 
 AC_MSG_NOTICE([checking for device files])