When trying to retrieve issues from a project with no issues, there is a typecast issue from the xml conversion.

I am using Redmine trunk, Rails 2.3.11

Sample code:

#!/usr/local/bin/ruby

require 'rubygems'
require 'active_resource'


class Issue < ActiveResource::Base
  self.site = 'http://demo.redmine.org/'
end

issue = Issue.find(:first, :params => { :project_id => 3 })

And the output:

/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/core_ext/hash/conversions.rb:99:in `typecast_xml_value': can't typecast "" (RuntimeError)
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/core_ext/hash/conversions.rb:121:in `typecast_xml_value'
        from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:29:in `inject'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/core_ext/hash/conversions.rb:120:in `each'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/core_ext/hash/conversions.rb:120:in `inject'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/core_ext/hash/conversions.rb:120:in `typecast_xml_value'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/core_ext/hash/conversions.rb:78:in `from_xml'
        from /usr/local/lib/ruby/gems/1.8/gems/activeresource-2.3.11/lib/active_resource/formats/xml_format.rb:22:in `decode'
        from /usr/local/lib/ruby/gems/1.8/gems/activeresource-2.3.11/lib/active_resource/connection.rb:79:in `get'
        from /usr/local/lib/ruby/gems/1.8/gems/activeresource-2.3.11/lib/active_resource/connection.rb:217:in `with_auth'
        from /usr/local/lib/ruby/gems/1.8/gems/activeresource-2.3.11/lib/active_resource/connection.rb:79:in `get'
        from /usr/local/lib/ruby/gems/1.8/gems/activeresource-2.3.11/lib/active_resource/base.rb:857:in `find_every'
        from /usr/local/lib/ruby/gems/1.8/gems/activeresource-2.3.11/lib/active_resource/base.rb:778:in `find'

The problem is different from #4745 and #5226. Let's examine the xml returned from the call:

Ok, that looks fine. Let's see how it's turned into an ActiveResource:

{"type"=>"array", "total_count"=>"0", "limit"=>"25", "offset"=>"0"}

This last line is passed into typecast_xml_value in /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/core_ext/hash/conversions.rb. In this code, it will do the following:

_, entries = Array.wrap(value.detect { |k,v| k != 'type' })
if entries.nil? || (c = value['__content__'] && c.blank?)
  []
else
  case entries.class.to_s
  when "Array"
  when "Hash"
  else
    raise "can't typecast #{entries.inspect}
  end

The first line sets entries to "0" (or whatever is the value of the next key), so it will always hit the exception. The seoncd line shows that an explicit empty key content is used to detect an empty array. Thus, if I patch index.api.rsb:

+if @issues.empty?
+  api.array :issues, api_meta( :__content__ => '', :total_count => @issue_count, :offset => @offset, :limit => @limit)
+else
...

Then the returned xml is correct. This patch will not work however because it interferes with the json format, which works fine by representing an empty array with []. I've attached the simple script, a proposed patch that fixes the problem but breaks json, and a test. It may be that the json/xml template needs to be split again.