hunk.code_window:                 checkPreference();
               },
               (err) => {
                   AsyncClient.dispatchError(err, 'getChannel');
               }
  
hunk.labels: keep replace replace replace keep
hunk.file_path: webapp/actions/user_actions.jsx
hunk.type: replace
file: /*-
   * Copyright 2014 Square Inc.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package josecipher
  
  import (
  	"crypto"
  	"encoding/binary"
  	"hash"
  	"io"
  )
  
  type concatKDF struct {
  	z, info []byte
  	i       uint32
  	cache   []byte
  	hasher  hash.Hash
  }
  
  // NewConcatKDF builds a KDF reader based on the given inputs.
  func NewConcatKDF(hash crypto.Hash, z, algID, ptyUInfo, ptyVInfo, supPubInfo, supPrivInfo []byte) io.Reader {
  	buffer := make([]byte, uint64(len(algID))+uint64(len(ptyUInfo))+uint64(len(ptyVInfo))+uint64(len(supPubInfo))+uint64(len(supPrivInfo)))
  	n := 0
  	n += copy(buffer, algID)
  	n += copy(buffer[n:], ptyUInfo)
  	n += copy(buffer[n:], ptyVInfo)
  	n += copy(buffer[n:], supPubInfo)
  	copy(buffer[n:], supPrivInfo)
  
  	hasher := hash.New()
  
  	return &concatKDF{
  		z:      z,
  		info:   buffer,
  		hasher: hasher,
  		cache:  []byte{},
  		i:      1,
  	}
  }
  
  func (ctx *concatKDF) Read(out []byte) (int, error) {
  	copied := copy(out, ctx.cache)
  	ctx.cache = ctx.cache[copied:]
  
  	for copied < len(out) {
  		ctx.hasher.Reset()
  
  		// Write on a hash.Hash never fails
  		_ = binary.Write(ctx.hasher, binary.BigEndian, ctx.i)
  		_, _ = ctx.hasher.Write(ctx.z)
  		_, _ = ctx.hasher.Write(ctx.info)
  
  		hash := ctx.hasher.Sum(nil)
  		chunkCopied := copy(out[copied:], hash)
  		copied += chunkCopied
  		ctx.cache = hash[chunkCopied:]
  
  		ctx.i++
  	}
  
  	return copied, nil
  }
  