+ AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+
+ dnl Persuade glibc <unistd.h> to declare {get,set,end}usershell().
+ AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+ AC_REPLACE_FUNCS([getusershell])
+ if test $ac_cv_func_getusershell = no; then
+ HAVE_GETUSERSHELL=0
+ fi