Handle case where Xft is found but not XRender

* configure.ac (XFT_LIBS): Ensure that HAVE_XFT is no if
XRender is not found.  (Bug#31634)

configure.ac

@@ -3210,8 +3210,8 @@ if test "${HAVE_X11}" = "yes"; then
     if test "x${with_xft}" != "xno"; then
 
       EMACS_CHECK_MODULES([XFT], [xft >= 0.13.0], [], [HAVE_XFT=no])
-      ## Because xftfont.c uses XRenderQueryExtension, we also
-      ## need to link to -lXrender.
+      ## Because xterm.c uses XRenderQueryExtension when XFT is
+      ## enabled, we also need to link to -lXrender.
       HAVE_XRENDER=no
       AC_CHECK_LIB(Xrender, XRenderQueryExtension, HAVE_XRENDER=yes)
       if test "$HAVE_XFT" != no && test "$HAVE_XRENDER" != no; then
@@ -3234,6 +3234,9 @@ if test "${HAVE_X11}" = "yes"; then
 	CPPFLAGS=$OLD_CPPFLAGS
 	CFLAGS=$OLD_CFLAGS
 	LIBS=$OLD_LIBS
+      else
+      # Make sure XFT is disabled if we found XFT but not XRender
+	HAVE_XFT=no
       fi                          # "$HAVE_XFT" != no
     fi                            # "x${with_xft}" != "xno"