+ AC_CACHE_CHECK([whether linkat handles trailing slash correctly],
+ [gl_cv_func_linkat_slash],
+ [rm -rf conftest.a conftest.b conftest.c conftest.d
+ AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <unistd.h>
+ #include <fcntl.h>
+ #include <errno.h>
+ #include <stdio.h>
+ ]],
+ [[int result;
+ int fd;
+ /* Create a regular file. */
+ fd = open ("conftest.a", O_CREAT | O_EXCL | O_WRONLY, 0600);
+ if (fd < 0)
+ return 1;
+ if (write (fd, "hello", 5) < 5)
+ return 2;
+ if (close (fd) < 0)
+ return 3;
+ /* Test whether hard links are supported on the current
+ device. */
+ if (linkat (AT_FDCWD, "conftest.a", AT_FDCWD, "conftest.b",
+ AT_SYMLINK_FOLLOW) < 0)
+ return 0;
+ result = 0;
+ /* Test whether a trailing "/" is treated like "/.". */
+ if (linkat (AT_FDCWD, "conftest.a/", AT_FDCWD, "conftest.c",
+ AT_SYMLINK_FOLLOW) == 0)
+ result |= 4;
+ if (linkat (AT_FDCWD, "conftest.a", AT_FDCWD, "conftest.d/",
+ AT_SYMLINK_FOLLOW) == 0)
+ result |= 8;
+ return result;
+ ]])],
+ [gl_cv_func_linkat_slash=yes],
+ [gl_cv_func_linkat_slash=no],
+ [# Guess yes on glibc systems, no otherwise.
+ case "$host_os" in
+ *-gnu*) gl_cv_func_linkat_slash="guessing yes";;
+ *) gl_cv_func_linkat_slash="guessing no";;
+ esac
+ ])
+ rm -rf conftest.a conftest.b conftest.c conftest.d])
+ case "$gl_cv_func_linkat_slash" in
+ *yes) gl_linkat_slash_bug=0 ;;
+ *) gl_linkat_slash_bug=1 ;;
+ esac
+ if test "$gl_cv_func_linkat_follow" != yes \
+ || test $gl_linkat_slash_bug = 1; then