* configure.ac: Include X11/Xlib.h for XOpenDisplay. (Bug#68842)

Do not merge to master.

diff --git a/configure.ac b/configure.ac
index 78d5475f75acc503aaca2c0c1e465ff8bfcc8ed5..34a5a89bea9956890a3d9a693190ea3a884bde68 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -2697,7 +2697,7 @@ if test "${HAVE_X11}" = "yes"; then
 
   if test "${opsys}" = "gnu-linux"; then
     AC_CACHE_CHECK([whether X on GNU/Linux needs -b to link], [emacs_cv_b_link],
-    [AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],
+    [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <X11/Xlib.h>]],
      [[XOpenDisplay ("foo");]])],
      [xgnu_linux_first_failure=no],
      [xgnu_linux_first_failure=yes])
@@ -2706,7 +2706,7 @@ if test "${HAVE_X11}" = "yes"; then
       OLD_LIBS="$LIBS"
       CPPFLAGS="$CPPFLAGS -b i486-linuxaout"
       LIBS="$LIBS -b i486-linuxaout"
-      AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],
+      AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <X11/Xlib.h>]],
        [[XOpenDisplay ("foo");]])],
        [xgnu_linux_second_failure=no],
        [xgnu_linux_second_failure=yes])