hunk.code_window: 			if foundWithSuffix {
   				continue
   			}
   			if strings.ContainsAny(word, ".-:") {
   				// This word contains a character that may be the end of a sentence, so split further
   				splitWords := strings.FieldsFunc(word, func(c rune) bool {
   					return c == '.' || c == '-' || c == ':'
   				})
  
hunk.labels: keep keep keep keep replace keep keep keep keep
hunk.after_edit: 			if _, ok := systemMentions[word]; !ok && strings.HasPrefix(word, "@") {
   				ret.OtherPotentialMentions = append(ret.OtherPotentialMentions, word[1:])
   			} else if strings.ContainsAny(word, ".-:") {
  
hunk.file_path: app/notification.go
hunk.type: replace
file: // Copyright 2012 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  // Package xsrftoken provides methods for generating and validating secure XSRF tokens.
  package xsrftoken // import "golang.org/x/net/xsrftoken"
  
  import (
  	"crypto/hmac"
  	"crypto/sha1"
  	"crypto/subtle"
  	"encoding/base64"
  	"fmt"
  	"strconv"
  	"strings"
  	"time"
  )
  
  // Timeout is the duration for which XSRF tokens are valid.
  // It is exported so clients may set cookie timeouts that match generated tokens.
  const Timeout = 24 * time.Hour
  
  // clean sanitizes a string for inclusion in a token by replacing all ":"s.
  func clean(s string) string {
  	return strings.Replace(s, ":", "_", -1)
  }
  
  // Generate returns a URL-safe secure XSRF token that expires in 24 hours.
  //
  // key is a secret key for your application; it must be non-empty.
  // userID is an optional unique identifier for the user.
  // actionID is an optional action the user is taking (e.g. POSTing to a particular path).
  func Generate(key, userID, actionID string) string {
  	return generateTokenAtTime(key, userID, actionID, time.Now())
  }
  
  // generateTokenAtTime is like Generate, but returns a token that expires 24 hours from now.
  func generateTokenAtTime(key, userID, actionID string, now time.Time) string {
  	if len(key) == 0 {
  		panic("zero length xsrf secret key")
  	}
  	// Round time up and convert to milliseconds.
  	milliTime := (now.UnixNano() + 1e6 - 1) / 1e6
  
  	h := hmac.New(sha1.New, []byte(key))
  	fmt.Fprintf(h, "%s:%s:%d", clean(userID), clean(actionID), milliTime)
  
  	// Get the padded base64 string then removing the padding.
  	tok := string(h.Sum(nil))
  	tok = base64.URLEncoding.EncodeToString([]byte(tok))
  	tok = strings.TrimRight(tok, "=")
  
  	return fmt.Sprintf("%s:%d", tok, milliTime)
  }
  
  // Valid reports whether a token is a valid, unexpired token returned by Generate.
  func Valid(token, key, userID, actionID string) bool {
  	return validTokenAtTime(token, key, userID, actionID, time.Now())
  }
  
  // validTokenAtTime reports whether a token is valid at the given time.
  func validTokenAtTime(token, key, userID, actionID string, now time.Time) bool {
  	if len(key) == 0 {
  		panic("zero length xsrf secret key")
  	}
  	// Extract the issue time of the token.
  	sep := strings.LastIndex(token, ":")
  	if sep < 0 {
  		return false
  	}
  	millis, err := strconv.ParseInt(token[sep+1:], 10, 64)
  	if err != nil {
  		return false
  	}
  	issueTime := time.Unix(0, millis*1e6)
  
  	// Check that the token is not expired.
  	if now.Sub(issueTime) >= Timeout {
  		return false
  	}
  
  	// Check that the token is not from the future.
  	// Allow 1 minute grace period in case the token is being verified on a
  	// machine whose clock is behind the machine that issued the token.
  	if issueTime.After(now.Add(1 * time.Minute)) {
  		return false
  	}
  
  	expected := generateTokenAtTime(key, userID, actionID, issueTime)
  
  	// Check that the token matches the expected value.
  	// Use constant time comparison to avoid timing attacks.
  	return subtle.ConstantTimeCompare([]byte(token), []byte(expected)) == 1
  }
  