Plan 9 support, try 2: continue with syscall.ELOOP for unix

Signed-off-by: Ronald G Minnich <[email protected]>

Author: rminnich

errors_plan9.go

@@ -0,0 +1,9 @@
+// Copyright (C) 2014-2015 Docker Inc & Go Authors. All rights reserved.
+// Copyright (C) 2017-2025 SUSE LLC. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package securejoin
+
+// ErrLoop is returned when too many symbolic links are encountered.
+var ErrLoop = errors.New("Too many symbolic links were encountered in translating the pathname")

errors_unix.go

@@ -0,0 +1,13 @@
+// Copyright (C) 2014-2015 Docker Inc & Go Authors. All rights reserved.
+// Copyright (C) 2017-2025 SUSE LLC. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !plan9
+
+package securejoin
+
+import "syscall"
+
+// ErrLoop is returned when too many symbolic links are encountered.
+var ErrLoop = syscall.ELOOP

join.go

@@ -15,9 +15,6 @@ import (
 
 const maxSymlinkLimit = 255
 
-// ErrLoop is returned when too many symbolic links are encountered.
-var ErrLoop = errors.New("Too many symbolic links were encountered in translating the pathname")
-
 // IsNotExist tells you if err is an error that implies that either the path
 // accessed does not exist (or path components don't exist). This is
 // effectively a more broad version of [os.IsNotExist].