vendor: github.com/Zillode/notify is now github.com/syncthing/notify (#4813)

Given that we've taken on the resposibility of maintaining this forked
package I've added it to the Syncthing organization. We still vendor it
like an external package, because it's convenient to keep it as a fork
of upstream to easier merge and file pull requests towards them.

vendor/github.com/syncthing/notify/util.go

@@ -0,0 +1,150 @@
+// Copyright (c) 2014-2015 The Notify Authors. All rights reserved.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+package notify
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const all = ^Event(0)
+const sep = string(os.PathSeparator)
+
+var errDepth = errors.New("exceeded allowed iteration count (circular symlink?)")
+
+func min(i, j int) int {
+	if i > j {
+		return j
+	}
+	return i
+}
+
+func max(i, j int) int {
+	if i < j {
+		return j
+	}
+	return i
+}
+
+// must panics if err is non-nil.
+func must(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+// nonil gives first non-nil error from the given arguments.
+func nonil(err ...error) error {
+	for _, err := range err {
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func cleanpath(path string) (realpath string, isrec bool, err error) {
+	if strings.HasSuffix(path, "...") {
+		isrec = true
+		path = path[:len(path)-3]
+	}
+	if path, err = filepath.Abs(path); err != nil {
+		return "", false, err
+	}
+	if path, err = canonical(path); err != nil {
+		return "", false, err
+	}
+	return path, isrec, nil
+}
+
+// canonical resolves any symlink in the given path and returns it in a clean form.
+// It expects the path to be absolute. It fails to resolve circular symlinks by
+// maintaining a simple iteration limit.
+func canonical(p string) (string, error) {
+	p, err := filepath.Abs(p)
+	if err != nil {
+		return "", err
+	}
+	for i, j, depth := 1, 0, 1; i < len(p); i, depth = i+1, depth+1 {
+		if depth > 128 {
+			return "", &os.PathError{Op: "canonical", Path: p, Err: errDepth}
+		}
+		if j = strings.IndexRune(p[i:], '/'); j == -1 {
+			j, i = i, len(p)
+		} else {
+			j, i = i, i+j
+		}
+		fi, err := os.Lstat(p[:i])
+		if err != nil {
+			return "", err
+		}
+		if fi.Mode()&os.ModeSymlink == os.ModeSymlink {
+			s, err := os.Readlink(p[:i])
+			if err != nil {
+				return "", err
+			}
+			if filepath.IsAbs(s) {
+				p = "/" + s + p[i:]
+			} else {
+				p = p[:j] + s + p[i:]
+			}
+			i = 1 // no guarantee s is canonical, start all over
+		}
+	}
+	return filepath.Clean(p), nil
+}
+
+func joinevents(events []Event) (e Event) {
+	if len(events) == 0 {
+		e = All
+	} else {
+		for _, event := range events {
+			e |= event
+		}
+	}
+	return
+}
+
+func split(s string) (string, string) {
+	if i := lastIndexSep(s); i != -1 {
+		return s[:i], s[i+1:]
+	}
+	return "", s
+}
+
+func base(s string) string {
+	if i := lastIndexSep(s); i != -1 {
+		return s[i+1:]
+	}
+	return s
+}
+
+func indexbase(root, name string) int {
+	if n, m := len(root), len(name); m >= n && name[:n] == root &&
+		(n == m || name[n] == os.PathSeparator) {
+		return min(n+1, m)
+	}
+	return -1
+}
+
+func indexSep(s string) int {
+	for i := 0; i < len(s); i++ {
+		if s[i] == os.PathSeparator {
+			return i
+		}
+	}
+	return -1
+}
+
+func lastIndexSep(s string) int {
+	for i := len(s) - 1; i >= 0; i-- {
+		if s[i] == os.PathSeparator {
+			return i
+		}
+	}
+	return -1
+}