+# Determine whether chown follows symlinks (it should).
+AC_DEFUN([gl_FUNC_CHOWN_FOLLOWS_SYMLINK],
+[
+ AC_CACHE_CHECK(
+ [whether chown(2) dereferences symlinks],
+ gl_cv_func_chown_follows_symlink,
+ [
+ AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+
+ int
+ main ()
+ {
+ char const *dangling_symlink = "conftest.dangle";
+
+ unlink (dangling_symlink);
+ if (symlink ("conftest.no-such", dangling_symlink))
+ abort ();
+
+ /* Exit successfully on a conforming system,
+ i.e., where chown must fail with ENOENT. */
+ exit ( ! (chown (dangling_symlink, getuid (), getgid ()) != 0
+ && errno == ENOENT));
+ }
+ ]])],
+ [gl_cv_func_chown_follows_symlink=yes],
+ [gl_cv_func_chown_follows_symlink=no],
+ [gl_cv_func_chown_follows_symlink=yes]
+ )
+ ]
+ )
+
+ if test $gl_cv_func_chown_follows_symlink = no; then
+ AC_DEFINE(CHOWN_MODIFIES_SYMLINK, 1,
+ [Define if chown modifies symlinks.])
+ fi
+])
+