New upstream version 1.8

[debian/gzip] / m4 / unlinkat.m4

diff --git a/m4/unlinkat.m4 b/m4/unlinkat.m4
new file mode 100644 (file)
index 0000000..e0da09f
--- /dev/null
+++ b/m4/unlinkat.m4
@@ -0,0 +1,34 @@
+# unlinkat.m4 serial 2
+dnl Copyright (C) 2004-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Written by Jim Meyering.
+
+AC_DEFUN([gl_FUNC_UNLINKAT],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_FUNCS_ONCE([unlinkat])
+  AC_REQUIRE([gl_FUNC_UNLINK])
+  AC_REQUIRE([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK])
+  if test $ac_cv_func_unlinkat = no; then
+    HAVE_UNLINKAT=0
+  else
+    case "$gl_cv_func_lstat_dereferences_slashed_symlink" in
+      *no)
+        # Solaris 9 has *at functions, but uniformly mishandles trailing
+        # slash in all of them.
+        REPLACE_UNLINKAT=1
+        ;;
+      *)
+        # GNU/Hurd has unlinkat, but it has the same bug as unlink.
+        # Darwin has unlinkat, but it has the same UNLINK_PARENT_BUG.
+        if test $REPLACE_UNLINK = 1; then
+          REPLACE_UNLINKAT=1
+        fi
+        ;;
+    esac
+  fi
+])