+ else
+ AC_CACHE_CHECK([whether ptsname sets errno on failure],
+ [gl_cv_func_ptsname_sets_errno],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM([[#include <errno.h>
+ ]], [[
+ return ptsname (-1) || !errno;
+ ]])],
+ [gl_cv_func_ptsname_sets_errno=yes],
+ [gl_cv_func_ptsname_sets_errno=no],
+ [case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu*) gl_cv_func_ptsname_sets_errno="guessing yes" ;;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_ptsname_sets_errno="guessing no" ;;
+ esac
+ ])])
+ case $gl_cv_func_ptsname_sets_errno in
+ *no) REPLACE_PTSNAME=1 ;;
+ esac