NoMethodError in ShelfController#category

undefined method `listtype=' for nil:NilClass

Extracted source (around line #554):
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shelf = getshelf
# logger.debug "Category: shelf=#{shelf}"
shelf.listtype = params[:list]
categories = Set.new
shelf.entries.each { |entry|

Rails.root: /app

Application Trace | Framework Trace | Full Trace

Request

Parameters:

{"list"=>"text", "shelfname"=>"%E3%81%9F%E3%80%80%E3%81%AE%E8%AA%AD%E6%9B%B8%E8%A8%98%E9%8C%B2"}

Response

Headers:

None