Index: app/controllers/issue_categories_controller.rb
===================================================================
--- app/controllers/issue_categories_controller.rb	(revision 20585)
+++ app/controllers/issue_categories_controller.rb	(working copy)
@@ -29,7 +29,7 @@
   def index
     respond_to do |format|
       format.html {redirect_to_settings_in_projects}
-      format.api {@categories = @project.issue_categories.to_a}
+      format.api {@categories = @project.issue_categories.sorted.to_a}
     end
   end
 
@@ -85,6 +85,7 @@
           flash[:notice] = l(:notice_successful_update)
           redirect_to_settings_in_projects
         end
+        format.js {head 200}
         format.api {render_api_ok}
       end
     else
@@ -91,6 +92,7 @@
       respond_to do |format|
         format.html {render :action => 'edit'}
         format.api {render_validation_errors(@category)}
+        format.js {head 422}
       end
     end
   end
Index: app/models/issue_category.rb
===================================================================
--- app/models/issue_category.rb	(revision 20585)
+++ app/models/issue_category.rb	(working copy)
@@ -22,13 +22,15 @@
   belongs_to :project
   belongs_to :assigned_to, :class_name => 'Principal'
   has_many :issues, :foreign_key => 'category_id', :dependent => :nullify
+  acts_as_positioned
 
   validates_presence_of :name
   validates_uniqueness_of :name, :scope => [:project_id]
   validates_length_of :name, :maximum => 60
 
-  safe_attributes 'name', 'assigned_to_id'
+  safe_attributes 'name', 'assigned_to_id', 'position'
 
+  scope :sorted, lambda {order(:position)}
   scope :named, lambda {|arg| where("LOWER(#{table_name}.name) = LOWER(?)", arg.to_s.strip)}
 
   alias :destroy_without_reassign :destroy
@@ -43,7 +45,7 @@
   end
 
   def <=>(category)
-    name <=> category.name
+    position <=> category.position
   end
 
   def to_s; name end
Index: app/models/project.rb
===================================================================
--- app/models/project.rb	(revision 20585)
+++ app/models/project.rb	(working copy)
@@ -46,7 +46,7 @@
   has_many :queries, :dependent => :delete_all
   has_many :documents, :dependent => :destroy
   has_many :news, lambda {includes(:author)}, :dependent => :destroy
-  has_many :issue_categories, lambda {order(:name)}, :dependent => :delete_all
+  has_many :issue_categories, lambda {order(:position)}, :dependent => :delete_all
   has_many :boards, lambda {order(:position)}, :inverse_of => :project, :dependent => :destroy
   has_one :repository, lambda {where(:is_default => true)}
   has_many :repositories, :dependent => :destroy
Index: app/views/projects/settings/_issue_categories.html.erb
===================================================================
--- app/views/projects/settings/_issue_categories.html.erb	(revision 20585)
+++ app/views/projects/settings/_issue_categories.html.erb	(working copy)
@@ -1,7 +1,7 @@
 <p><%= link_to l(:label_issue_category_new), new_project_issue_category_path(@project), :class => 'icon icon-add' if User.current.allowed_to?(:manage_categories, @project) %></p>
 
 <% if @project.issue_categories.any? %>
-<table class="list">
+<table class="list issue_categories">
   <thead><tr>
     <th><%= l(:label_issue_category) %></th>
     <th><%= l(:field_assigned_to) %></th>
@@ -15,6 +15,7 @@
     <td><%= category.assigned_to.name if category.assigned_to %></td>
     <td class="buttons">
       <% if User.current.allowed_to?(:manage_categories, @project) %>
+        <%= reorder_handle category %>
         <%= link_to l(:button_edit), edit_issue_category_path(category), :class => 'icon icon-edit' %>
         <%= delete_link issue_category_path(category) %>
       <% end %>
@@ -27,3 +28,7 @@
 <% else %>
 <p class="nodata"><%= l(:label_no_data) %></p>
 <% end %>
+
+<%= javascript_tag do %>
+  $(function() { $("table.issue_categories tbody").positionedItems(); });
+<% end %>
Index: config/routes.rb
===================================================================
--- config/routes.rb	(revision 20585)
+++ config/routes.rb	(working copy)
@@ -127,7 +127,7 @@
     end
 
     member do
-      get 'settings(/:tab)', :action => 'settings', :as => 'settings'
+      match 'settings(/:tab)', action: 'settings', as: 'settings', via: [:get, :put]
       post 'archive'
       post 'unarchive'
       post 'close'
Index: db/migrate/20201209122301_add_issue_category_position.rb
===================================================================
--- db/migrate/20201209122301_add_issue_category_position.rb	(nonexistent)
+++ db/migrate/20201209122301_add_issue_category_position.rb	(working copy)
@@ -0,0 +1,10 @@
+class AddIssueCategoryPosition < ActiveRecord::Migration[5.2]
+  def self.up
+    add_column :issue_categories, :position, :integer, default: 1
+    IssueCategory.order(:name).each_with_index { |category, i| category.update_attribute(:position, i + 1) }
+  end
+
+  def self.down
+    remove_column :issue_categories, :position
+  end
+end
Index: test/fixtures/issue_categories.yml
===================================================================
--- test/fixtures/issue_categories.yml	(revision 20585)
+++ test/fixtures/issue_categories.yml	(working copy)
@@ -3,19 +3,23 @@
   name: Printing
   project_id: 1
   assigned_to_id: 2
+  position: 1
   id: 1
 issue_categories_002: 
   name: Recipes
   project_id: 1
-  assigned_to_id: 
+  assigned_to_id:
+  position: 2
   id: 2
 issue_categories_003: 
   name: Stock management
   project_id: 2
-  assigned_to_id: 
+  assigned_to_id:
+  position: 3
   id: 3
 issue_categories_004: 
   name: Printing
   project_id: 2
-  assigned_to_id: 
+  assigned_to_id:
+  position: 4
   id: 4
Index: test/functional/issue_categories_controller_test.rb
===================================================================
--- test/functional/issue_categories_controller_test.rb	(revision 20585)
+++ test/functional/issue_categories_controller_test.rb	(working copy)
@@ -137,13 +137,16 @@
         :params => {
           :id => 2,
           :issue_category => {
-            :name => 'Testing'
+            :name => 'Testing',
+            :position => 3
           }
         }
       )
     end
     assert_redirected_to '/projects/ecookbook/settings/categories'
-    assert_equal 'Testing', IssueCategory.find(2).name
+    issue_category = IssueCategory.find(2)
+    assert_equal 'Testing', issue_category.name
+    assert_equal 3, issue_category.position
   end
 
   def test_update_failure
Index: test/unit/issue_category_test.rb
===================================================================
--- test/unit/issue_category_test.rb	(revision 20585)
+++ test/unit/issue_category_test.rb	(working copy)
@@ -31,6 +31,7 @@
     assert IssueCategory.new(:project_id => 2, :name => 'New category').save
     category = IssueCategory.order('id DESC').first
     assert_equal 'New category', category.name
+    assert_equal 1, category.position
   end
 
   def test_create_with_group_assignment