Hi, I'm really interested in this topic and I could reproduce this problem in my env.
I'm not sure this workaround is correctly, but I could manage to call extended method 'test_hello' like this;

test_001¶

# test001/init.rb

require 'test_issues_controller_patch'

Redmine::Plugin.register :test_001 do
  name 'Test 001 plugin'
  author 'Author name'
  description 'This is a plugin for Redmine'
  version '0.0.1'
  url 'http://example.com/path/to/plugin'
  author_url 'http://example.com/about'
end

Rails.configuration.to_prepare do
  unless IssuesController.included_modules.include?(TestIssuesControllerPatch)
    IssuesController.send :include, TestIssuesControllerPatch  # only loaded once at initialized plugin
  end
end

# test001/lib/test_issues_controller_patch.rb

module TestIssuesControllerPatch
  extend ActiveSupport::Concern
  included do
  end
end

test_002¶

# test_002/init.rb

require 'test_hooks'
require 'test_issues_helper_patch'

Redmine::Plugin.register :test_002 do
  name 'Test 002 plugin'
  author 'Author name'
  description 'This is a plugin for Redmine'
  version '0.0.1'
  url 'http://example.com/path/to/plugin'
  author_url 'http://example.com/about'
end

Rails.configuration.to_prepare do
   # do nothing
end

# test_002/lib/test_hook.rb

class TestHooks < Redmine::Hook::ViewListener
  def view_issues_show_details_bottom(context={})
    context[:hook_caller].instance_eval do
      render(:partial => 'test/hello_world')
    end
  end
end

# test_002/lib/test_issues_helper_patch.rb

module TestIssuesHelperPatch
  extend ActiveSupport::Concern
  included do
  end

  def test_hello
    'hello world'
  end
end

IssuesHelper.send :prepend, TestIssuesHelperPatch # change from include to prepend

# test_002/app/views/test/_hello_world.html.erb

  <!-- prevent method missing exception -->
  <% if defined?(test_hello)  %>
      <%= test_hello %>
  <% end %>

As results, test_hello method is appended at the first of method chain.

>> IssuesHelper.instance_methods
[:test_hello, :render_issue_tooltip, :issue_list, :grouped_issue_list,  ..... ]

>> IssuesHelper.ancestors
[TestIssuesHelperPatch, IssuesHelper, Redmine::Export::PDF::IssuesPdfHelper, ApplicationHelper, Redmine::Helpers::URL, Redmine::Hook::Helper, Redmine::Themes::Helper, Redmine::SudoMode::Helper, Redmine::Pagination::Helper, GravatarHelper::PublicMethods, Redmine::I18n, Redmine::WikiFormatting::Macros::Definitions]

Since TestIssueController patch is empty, I'm not sure if the controller patch also works fine.
But I hope to this would be any help and I'm looking forward to any comments, corrections, advise from you and redmine experts.

Found this during investigation on a similar issue.
I could solve this by moving the 'offending' ControllerPatch to after_initialize callback.

For the example here that would mean to simply transform

Rails.configuration.to_prepare do
  unless IssuesController.included_modules.include?(TestIssuesControllerPatch)
    IssuesController.send :include, TestIssuesControllerPatch  # only loaded once at initialized plugin
  end
end

into

Rails.configuration.after_initialize do
  unless IssuesController.included_modules.include?(TestIssuesControllerPatch)
    IssuesController.send :include, TestIssuesControllerPatch  # only loaded once at initialized plugin
  end
end

Hi, Stephan!

The version of Redmine that everyone mainly use will soon be 4.x, then 3.x.
Since I always struggle with plug-in combinations, so your information above is helpful.

Stephan Wiehr wrote:

Found this during investigation on a similar issue.
I could solve this by moving the 'offending' ControllerPatch to after_initialize callback.