Redmine

Environment: CentOS, Redmine 3.0.1, using Rails 4.2 and MS SQL database 2012 (through activerecord-sqlserver-adapter-4.2.4)

On a project, filter issues and group them by category.
When trying that on our test deployment of Redmine 3.0.1, I got an Error 500, with the following message:
TinyTds::Error: A column has been specified more than once in the order by list. Columns in the order by list must be unique. SELECT [issues].[id] AS t0_r0 (...) ORDER BY issue_categories.name ASC, (CASE WHEN versions.effective_date IS NULL THEN 1 ELSE 0 END), versions.effective_date, versions.name, versions.id, enumerations.position DESC, issue_categories.name OFFSET 0 ROWS FETCH NEXT 100 ROWS ONLY

It seems that group_by_sort_order from app/models/query.rb adds the first issue_categories.name ASC, but issue_categories.name is also contained in the order_by options when merged in app/models/issue_query.rb:

def issues(options={})
    order_option = [group_by_sort_order, options[:order]].flatten.reject(&:blank?)

which results in duplicated columns. It did not cause any error when using Rails 3.2, and Redmine 2.6.1.

Can you confirm you reproduce?
I fixed it by adding

dup_index = order_option.rindex{|s| s[/#{group_by_sort_order.split(" ")[0]}/]}
    if dup_index > 0
      order_option.delete_at(dup_index)
    end

in the issues() function after merging order options, but I'm not sure this is the right way to do it (maybe it should not be present in options[:order] in the first place?).