+# gl_FUNC_FCHOWNAT_EMPTY_FILENAME_BUG([ACTION-IF-BUGGY[, ACTION-IF-NOT_BUGGY]])
+AC_DEFUN([gl_FUNC_FCHOWNAT_EMPTY_FILENAME_BUG],
+[
+ dnl Persuade glibc's <unistd.h> to declare fchownat().
+ AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+ AC_CACHE_CHECK([whether fchownat works with an empty file name],
+ [gl_cv_func_fchownat_empty_filename_works],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <unistd.h>
+ #include <fcntl.h>
+ ]],
+ [[int fd;
+ int ret;
+ if (mkdir ("conftestdir", 0700) < 0)
+ return 2;
+ fd = open ("conftestdir", O_RDONLY);
+ if (fd < 0)
+ return 3;
+ ret = fchownat (fd, "", -1, -1, 0);
+ close (fd);
+ rmdir ("conftestdir");
+ return ret == 0;
+ ]])],
+ [gl_cv_func_fchownat_empty_filename_works=yes],
+ [gl_cv_func_fchownat_empty_filename_works=no],
+ [gl_cv_func_fchownat_empty_filename_works="guessing no"])
+ ])
+ AS_IF([test "$gl_cv_func_fchownat_empty_filename_works" != yes], [$1], [$2])
+])
+