Adds subtasking (#443) including:

* priority, start/due dates, progress, estimate, spent time roll-up to parent issues
* descendant issues tree displayed on the issue view with context menu support
* issue tree display on the gantt chart
* issue tree copy on project copy
* unlimited nesting

Defining subtasks requires the new permission 'Manage subtasks'.
Subtasks can not belong to a different project than the parent task.

Implementation is based on scoped nested sets for fast reads and updates.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@3573 e93f8b46-1217-0410-a6f0-8f06a7374b81

11 files changed, 328 insertions, 67 deletions

diff --git a/app/controllers/issues_controller.rb b/app/controllers/issues_controller.rb
index cd61fdc37..4a8c56ea9 100644
--- a/app/controllers/issues_controller.rb
+++ b/app/controllers/issues_controller.rb
@@ -21,7 +21,7 @@ class IssuesController < ApplicationController
   
   before_filter :find_issue, :only => [:show, :edit, :update, :reply]
   before_filter :find_issues, :only => [:bulk_edit, :move, :destroy]
-  before_filter :find_project, :only => [:new, :update_form, :preview]
+  before_filter :find_project, :only => [:new, :update_form, :preview, :auto_complete]
   before_filter :authorize, :except => [:index, :changes, :gantt, :calendar, :preview, :context_menu]
   before_filter :find_optional_project, :only => [:index, :changes, :gantt, :calendar]
   accept_key_auth :index, :show, :changes
@@ -164,7 +164,8 @@ class IssuesController < ApplicationController
         call_hook(:controller_issues_new_after_save, { :params => params, :issue => @issue})
         respond_to do |format|
           format.html {
-            redirect_to(params[:continue] ? { :action => 'new', :tracker_id => @issue.tracker } :
+            redirect_to(params[:continue] ? { :action => 'new', :issue => {:tracker_id => @issue.tracker, 
+                                                                           :parent_issue_id => @issue.parent_issue_id}.reject {|k,v| v.nil?} } :
                                             { :action => 'show', :id => @issue })
           }
           format.xml  { render :action => 'show', :status => :created, :location => url_for(:controller => 'issues', :action => 'show', :id => @issue) }
@@ -247,6 +248,7 @@ class IssuesController < ApplicationController
   
   # Bulk edit a set of issues
   def bulk_edit
+    @issues.sort!
     if request.post?
       attributes = (params[:issue] || {}).reject {|k,v| v.blank?}
       attributes.keys.each {|k| attributes[k] = '' if attributes[k] == 'none'}
@@ -254,6 +256,7 @@ class IssuesController < ApplicationController
       
       unsaved_issue_ids = []
       @issues.each do |issue|
+        issue.reload
         journal = issue.init_journal(User.current, params[:notes])
         issue.safe_attributes = attributes
         call_hook(:controller_issues_bulk_edit_before_save, { :params => params, :issue => issue })
@@ -271,6 +274,7 @@ class IssuesController < ApplicationController
   end
 
   def move
+    @issues.sort!
     @copy = params[:copy_options] && params[:copy_options][:copy]
     @allowed_projects = []
     # find projects to which the user is allowed to move the issue
@@ -289,6 +293,7 @@ class IssuesController < ApplicationController
       unsaved_issue_ids = []
       moved_issues = []
       @issues.each do |issue|
+        issue.reload
         changed_attributes = {}
         [:assigned_to_id, :status_id, :start_date, :due_date].each do |valid_attribute|
           unless params[valid_attribute].blank?
@@ -297,7 +302,7 @@ class IssuesController < ApplicationController
         end
         issue.init_journal(User.current)
         call_hook(:controller_issues_move_before_save, { :params => params, :issue => issue, :target_project => @target_project, :copy => !!@copy })
-        if r = issue.move_to(@target_project, new_tracker, {:copy => @copy, :attributes => changed_attributes})
+        if r = issue.move_to_project(@target_project, new_tracker, {:copy => @copy, :attributes => changed_attributes})
           moved_issues << r
         else
           unsaved_issue_ids << issue.id
@@ -456,6 +461,18 @@ class IssuesController < ApplicationController
     render :partial => 'common/preview'
   end
   
+  def auto_complete
+    @issues = []
+    q = params[:q].to_s
+    if q.match(/^\d+$/)
+      @issues << @project.issues.visible.find_by_id(q.to_i)
+    end
+    unless q.blank?
+      @issues += @project.issues.visible.find(:all, :conditions => ["LOWER(#{Issue.table_name}.subject) LIKE ?", "%#{q.downcase}%"], :limit => 10)
+    end
+    render :layout => false
+  end
+  
 private
   def find_issue
     @issue = Issue.find(params[:id], :include => [:project, :tracker, :status, :author, :priority, :category])
diff --git a/app/controllers/timelog_controller.rb b/app/controllers/timelog_controller.rb
index c08815890..160c19974 100644
--- a/app/controllers/timelog_controller.rb
+++ b/app/controllers/timelog_controller.rb
@@ -94,7 +94,7 @@ class TimelogController < ApplicationController
       elsif @issue.nil?
         sql_condition = @project.project_condition(Setting.display_subprojects_issues?)
       else
-        sql_condition = "#{TimeEntry.table_name}.issue_id = #{@issue.id}"
+        sql_condition = "#{Issue.table_name}.root_id = #{@issue.root_id} AND #{Issue.table_name}.lft >= #{@issue.lft} AND #{Issue.table_name}.rgt <= #{@issue.rgt}"
       end
 
       sql = "SELECT #{sql_select}, tyear, tmonth, tweek, spent_on, SUM(hours) AS hours"
@@ -166,7 +166,7 @@ class TimelogController < ApplicationController
     elsif @issue.nil?
       cond << @project.project_condition(Setting.display_subprojects_issues?)
     else
-      cond << ["#{TimeEntry.table_name}.issue_id = ?", @issue.id]
+      cond << "#{Issue.table_name}.root_id = #{@issue.root_id} AND #{Issue.table_name}.lft >= #{@issue.lft} AND #{Issue.table_name}.rgt <= #{@issue.rgt}"
     end
     
     retrieve_date_range
@@ -176,7 +176,7 @@ class TimelogController < ApplicationController
       respond_to do |format|
         format.html {
           # Paginate results
-          @entry_count = TimeEntry.count(:include => :project, :conditions => cond.conditions)
+          @entry_count = TimeEntry.count(:include => [:project, :issue], :conditions => cond.conditions)
           @entry_pages = Paginator.new self, @entry_count, per_page_option, params['page']
           @entries = TimeEntry.find(:all, 
                                     :include => [:project, :activity, :user, {:issue => :tracker}],
@@ -184,7 +184,7 @@ class TimelogController < ApplicationController
                                     :order => sort_clause,
                                     :limit  =>  @entry_pages.items_per_page,
                                     :offset =>  @entry_pages.current.offset)
-          @total_hours = TimeEntry.sum(:hours, :include => :project, :conditions => cond.conditions).to_f
+          @total_hours = TimeEntry.sum(:hours, :include => [:project, :issue], :conditions => cond.conditions).to_f
 
           render :layout => !request.xhr?
         }
diff --git a/app/helpers/issues_helper.rb b/app/helpers/issues_helper.rb
index 8124add12..db21e9ab7 100644
--- a/app/helpers/issues_helper.rb
+++ b/app/helpers/issues_helper.rb
@@ -30,6 +30,34 @@ module IssuesHelper
       "<strong>#{@cached_label_assigned_to}</strong>: #{issue.assigned_to}<br />" +
       "<strong>#{@cached_label_priority}</strong>: #{issue.priority.name}"
   end
+    
+  def render_issue_subject_with_tree(issue)
+    s = ''
+    issue.ancestors.each do |ancestor|
+      s << '<div>' + content_tag('p', link_to_issue(ancestor))
+    end
+    s << '<div>' + content_tag('h3', h(issue.subject))
+    s << '</div>' * (issue.ancestors.size + 1)
+    s
+  end
+  
+  def render_descendants_tree(issue)
+    s = '<form><table class="list issues">'
+    ancestors = []
+    issue.descendants.sort_by(&:lft).each do |child|
+      level = child.level - issue.level - 1
+      s << content_tag('tr',
+             content_tag('td', check_box_tag("ids[]", child.id, false, :id => nil)) +
+             content_tag('td', link_to_issue(child), :class => 'subject',
+                                                     :style => "padding-left: #{level * 20}px") +
+             content_tag('td', h(child.status)) +
+             content_tag('td', link_to_user(child.assigned_to)) +
+             content_tag('td', progress_bar(child.done_ratio, :width => '80px')),
+             :class => "issue-#{child.id} hascontextmenu")
+    end
+    s << '</form></table>'
+    s
+  end
   
   def render_custom_fields_rows(issue)
     return if issue.custom_field_values.empty?
diff --git a/app/models/issue.rb b/app/models/issue.rb
index 6f78ff1e8..c39c9ce8f 100644
--- a/app/models/issue.rb
+++ b/app/models/issue.rb
@@ -32,6 +32,7 @@ class Issue < ActiveRecord::Base
   has_many :relations_from, :class_name => 'IssueRelation', :foreign_key => 'issue_from_id', :dependent => :delete_all
   has_many :relations_to, :class_name => 'IssueRelation', :foreign_key => 'issue_to_id', :dependent => :delete_all
   
+  acts_as_nested_set :scope => 'root_id'
   acts_as_attachable :after_remove => :attachment_removed
   acts_as_customizable
   acts_as_watchable
@@ -68,7 +69,9 @@ class Issue < ActiveRecord::Base
 
   before_create :default_assign
   before_save :reschedule_following_issues, :close_duplicates, :update_done_ratio_from_issue_status
-  after_save :create_journal
+  after_save :update_nested_set_attributes, :update_parent_attributes, :create_journal
+  after_destroy :destroy_children
+  after_destroy :update_parent_attributes
   
   # Returns true if usr or current user is allowed to view the issue
   def visible?(usr=nil)
@@ -90,60 +93,75 @@ class Issue < ActiveRecord::Base
   
   def copy_from(arg)
     issue = arg.is_a?(Issue) ? arg : Issue.find(arg)
-    self.attributes = issue.attributes.dup.except("id", "created_on", "updated_on")
-    self.custom_values = issue.custom_values.collect {|v| v.clone}
+    self.attributes = issue.attributes.dup.except("id", "root_id", "parent_id", "lft", "rgt", "created_on", "updated_on")
+    self.custom_field_values = issue.custom_field_values.inject({}) {|h,v| h[v.custom_field_id] = v.value; h}
     self.status = issue.status
     self
   end
   
   # Moves/copies an issue to a new project and tracker
   # Returns the moved/copied issue on success, false on failure
-  def move_to(new_project, new_tracker = nil, options = {})
-    options ||= {}
-    issue = options[:copy] ? self.clone : self
+  def move_to_project(*args)
     ret = Issue.transaction do
-      if new_project && issue.project_id != new_project.id
-        # delete issue relations
-        unless Setting.cross_project_issue_relations?
-          issue.relations_from.clear
-          issue.relations_to.clear
-        end
-        # issue is moved to another project
-        # reassign to the category with same name if any
-        new_category = issue.category.nil? ? nil : new_project.issue_categories.find_by_name(issue.category.name)
-        issue.category = new_category
-        # Keep the fixed_version if it's still valid in the new_project
-        unless new_project.shared_versions.include?(issue.fixed_version)
-          issue.fixed_version = nil
-        end
-        issue.project = new_project
-      end
-      if new_tracker
-        issue.tracker = new_tracker
+      move_to_project_without_transaction(*args) || raise(ActiveRecord::Rollback)
+    end || false
+  end
+  
+  def move_to_project_without_transaction(new_project, new_tracker = nil, options = {})
+    options ||= {}
+    issue = options[:copy] ? self.class.new.copy_from(self) : self
+    
+    if new_project && issue.project_id != new_project.id
+      # delete issue relations
+      unless Setting.cross_project_issue_relations?
+        issue.relations_from.clear
+        issue.relations_to.clear
       end
-      if options[:copy]
-        issue.custom_field_values = self.custom_field_values.inject({}) {|h,v| h[v.custom_field_id] = v.value; h}
-        issue.status = if options[:attributes] && options[:attributes][:status_id]
-                         IssueStatus.find_by_id(options[:attributes][:status_id])
-                       else
-                         self.status
-                       end
+      # issue is moved to another project
+      # reassign to the category with same name if any
+      new_category = issue.category.nil? ? nil : new_project.issue_categories.find_by_name(issue.category.name)
+      issue.category = new_category
+      # Keep the fixed_version if it's still valid in the new_project
+      unless new_project.shared_versions.include?(issue.fixed_version)
+        issue.fixed_version = nil
       end
-      # Allow bulk setting of attributes on the issue
-      if options[:attributes]
-        issue.attributes = options[:attributes]
+      issue.project = new_project
+      if issue.parent && issue.parent.project_id != issue.project_id
+        issue.parent_issue_id = nil
       end
-      if issue.save
-        unless options[:copy]
-          # Manually update project_id on related time entries
-          TimeEntry.update_all("project_id = #{new_project.id}", {:issue_id => id})
+    end
+    if new_tracker
+      issue.tracker = new_tracker
+      issue.reset_custom_values!
+    end
+    if options[:copy]
+      issue.custom_field_values = self.custom_field_values.inject({}) {|h,v| h[v.custom_field_id] = v.value; h}
+      issue.status = if options[:attributes] && options[:attributes][:status_id]
+                       IssueStatus.find_by_id(options[:attributes][:status_id])
+                     else
+                       self.status
+                     end
+    end
+    # Allow bulk setting of attributes on the issue
+    if options[:attributes]
+      issue.attributes = options[:attributes]
+    end
+    if issue.save
+      unless options[:copy]
+        # Manually update project_id on related time entries
+        TimeEntry.update_all("project_id = #{new_project.id}", {:issue_id => id})
+        
+        issue.children.each do |child|
+          unless child.move_to_project_without_transaction(new_project)
+            # Move failed and transaction was rollback'd
+            return false
+          end
         end
-        true
-      else
-        raise ActiveRecord::Rollback
       end
+    else
+      return false
     end
-    ret ? issue : false
+    issue
   end
   
   def priority_id=(pid)
@@ -177,6 +195,7 @@ class Issue < ActiveRecord::Base
   SAFE_ATTRIBUTES = %w(
     tracker_id
     status_id
+    parent_issue_id
     category_id
     assigned_to_id
     priority_id
@@ -203,6 +222,19 @@ class Issue < ActiveRecord::Base
         attrs.delete('status_id')
       end
     end
+    
+    unless leaf?
+      attrs.reject! {|k,v| %w(priority_id done_ratio start_date due_date estimated_hours).include?(k)}
+    end
+    
+    if attrs.has_key?('parent_issue_id')
+      if !user.allowed_to?(:manage_subtasks, project)
+        attrs.delete('parent_issue_id')
+      elsif !attrs['parent_issue_id'].blank?
+        attrs.delete('parent_issue_id') unless Issue.visible(user).exists?(attrs['parent_issue_id'])
+      end
+    end
+    
     self.attributes = attrs
   end
   
@@ -249,6 +281,22 @@ class Issue < ActiveRecord::Base
         errors.add :tracker_id, :inclusion
       end
     end
+    
+    # Checks parent issue assignment
+    if @parent_issue
+      if @parent_issue.project_id != project_id
+        errors.add :parent_issue_id, :not_same_project
+      elsif !new_record?
+        # moving an existing issue
+        if @parent_issue.root_id != root_id
+          # we can always move to another tree
+        elsif move_possible?(@parent_issue)
+          # move accepted inside tree
+        else
+          errors.add :parent_issue_id, :not_a_valid_parent
+        end
+      end
+    end
   end
   
   # Set the done_ratio using the status if that setting is set.  This will keep the done_ratios
@@ -340,13 +388,13 @@ class Issue < ActiveRecord::Base
     notified.collect(&:mail)
   end
   
-  # Returns the total number of hours spent on this issue.
+  # Returns the total number of hours spent on this issue and its descendants
   #
   # Example:
-  #   spent_hours => 0
-  #   spent_hours => 50
+  #   spent_hours => 0.0
+  #   spent_hours => 50.2
   def spent_hours
-    @spent_hours ||= time_entries.sum(:hours) || 0
+    @spent_hours ||= self_and_descendants.sum("#{TimeEntry.table_name}.hours", :include => :time_entries).to_f || 0.0
   end
   
   def relations
@@ -386,6 +434,16 @@ class Issue < ActiveRecord::Base
     @soonest_start ||= relations_to.collect{|relation| relation.successor_soonest_start}.compact.min
   end
   
+  def <=>(issue)
+    if issue.nil?
+      -1
+    elsif root_id != issue.root_id
+      (root_id || 0) <=> (issue.root_id || 0)
+    else
+      (lft || 0) <=> (issue.lft || 0)
+    end
+  end
+  
   def to_s
     "#{tracker} ##{id}: #{subject}"
   end
@@ -442,6 +500,24 @@ class Issue < ActiveRecord::Base
     Issue.update_versions(["#{Version.table_name}.project_id IN (?) OR #{Issue.table_name}.project_id IN (?)", moved_project_ids, moved_project_ids])
   end
 
+  def parent_issue_id=(arg)
+    parent_issue_id = arg.blank? ? nil : arg.to_i
+    if parent_issue_id && @parent_issue = Issue.find_by_id(parent_issue_id)
+      @parent_issue.id
+    else
+      @parent_issue = nil
+      nil
+    end
+  end
+  
+  def parent_issue_id
+    if instance_variable_defined? :@parent_issue
+      @parent_issue.nil? ? nil : @parent_issue.id
+    else
+      parent_id
+    end
+  end
+
   # Extracted from the ReportsController.
   def self.by_tracker(project)
     count_and_group_by(:project => project,
@@ -495,6 +571,95 @@ class Issue < ActiveRecord::Base
   
   private
   
+  def update_nested_set_attributes
+    if root_id.nil?
+      # issue was just created
+      self.root_id = (@parent_issue.nil? ? id : @parent_issue.root_id)
+      set_default_left_and_right
+      Issue.update_all("root_id = #{root_id}, lft = #{lft}, rgt = #{rgt}", ["id = ?", id])
+      if @parent_issue
+        move_to_child_of(@parent_issue)
+      end
+      reload
+    elsif parent_issue_id != parent_id
+      # moving an existing issue
+      if @parent_issue && @parent_issue.root_id == root_id
+        # inside the same tree
+        move_to_child_of(@parent_issue)
+      else
+        # to another tree
+        unless root?
+          move_to_right_of(root)
+          reload
+        end
+        old_root_id = root_id
+        self.root_id = (@parent_issue.nil? ? id : @parent_issue.root_id )
+        target_maxright = nested_set_scope.maximum(right_column_name) || 0
+        offset = target_maxright + 1 - lft
+        Issue.update_all("root_id = #{root_id}, lft = lft + #{offset}, rgt = rgt + #{offset}",
+                          ["root_id = ? AND lft >= ? AND rgt <= ? ", old_root_id, lft, rgt])
+        self[left_column_name] = lft + offset
+        self[right_column_name] = rgt + offset
+        if @parent_issue
+          move_to_child_of(@parent_issue)
+        end
+      end
+      reload
+      # delete invalid relations of all descendants
+      self_and_descendants.each do |issue|
+        issue.relations.each do |relation|
+          relation.destroy unless relation.valid?
+        end
+      end
+    end
+    remove_instance_variable(:@parent_issue) if instance_variable_defined?(:@parent_issue)
+  end
+  
+  def update_parent_attributes
+    if parent_id && p = Issue.find_by_id(parent_id)
+      # priority = highest priority of children
+      if priority_position = p.children.maximum("#{IssuePriority.table_name}.position", :include => :priority)
+        p.priority = IssuePriority.find_by_position(priority_position)
+      end
+      
+      # start/due dates = lowest/highest dates of children
+      p.start_date = p.children.minimum(:start_date)
+      p.due_date = p.children.maximum(:due_date)
+      if p.start_date && p.due_date && p.due_date < p.start_date
+        p.start_date, p.due_date = p.due_date, p.start_date
+      end
+      
+      # done ratio = weighted average ratio of leaves
+      unless Issue.use_status_for_done_ratio? && p.status && p.status.default_done_ratio?
+        leaves_count = p.leaves.count
+        if leaves_count > 0
+          average = p.leaves.average(:estimated_hours).to_f
+          if average == 0
+            average = 1
+          end
+          done = p.leaves.sum("COALESCE(estimated_hours, #{average}) * (CASE WHEN is_closed = #{connection.quoted_true} THEN 100 ELSE COALESCE(done_ratio, 0) END)", :include => :status).to_f
+          progress = done / (average * leaves_count)
+          p.done_ratio = progress.round
+        end
+      end
+      
+      # estimate = sum of leaves estimates
+      p.estimated_hours = p.leaves.sum(:estimated_hours).to_f
+      p.estimated_hours = nil if p.estimated_hours == 0.0
+      
+      # ancestors will be recursively updated
+      p.save(false)
+    end
+  end
+  
+  def destroy_children
+    unless leaf?
+      children.each do |child|
+        child.destroy
+      end
+    end
+  end
+  
   # Update issues so their versions are not pointing to a
   # fixed_version that is not shared with the issue's project
   def self.update_versions(conditions=nil)
@@ -562,7 +727,7 @@ class Issue < ActiveRecord::Base
   def create_journal
     if @current_journal
       # attributes changes
-      (Issue.column_names - %w(id description lock_version created_on updated_on)).each {|c|
+      (Issue.column_names - %w(id description root_id lft rgt lock_version created_on updated_on)).each {|c|
         @current_journal.details << JournalDetail.new(:property => 'attr',
                                                       :prop_key => c,
                                                       :old_value => @issue_before_change.send(c),
diff --git a/app/models/issue_relation.rb b/app/models/issue_relation.rb
index 6dd4ce4be..2c110a72f 100644
--- a/app/models/issue_relation.rb
+++ b/app/models/issue_relation.rb
@@ -48,6 +48,7 @@ class IssueRelation < ActiveRecord::Base
       errors.add :issue_to_id, :invalid if issue_from_id == issue_to_id
       errors.add :issue_to_id, :not_same_project unless issue_from.project_id == issue_to.project_id || Setting.cross_project_issue_relations?
       errors.add_to_base :circular_dependency if issue_to.all_dependent_issues.include? issue_from
+      errors.add_to_base :cant_link_an_issue_with_a_descendant if issue_from.is_descendant_of?(issue_to) || issue_from.is_ancestor_of?(issue_to)
     end
   end
   
diff --git a/app/models/project.rb b/app/models/project.rb
index d5941e095..8d6303224 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -557,9 +557,12 @@ class Project < ActiveRecord::Base
     # value.  Used to map the two togeather for issue relations.
     issues_map = {}
     
-    project.issues.each do |issue|
+    # Get issues sorted by root_id, lft so that parent issues
+    # get copied before their children
+    project.issues.find(:all, :order => 'root_id, lft').each do |issue|
       new_issue = Issue.new
       new_issue.copy_from(issue)
+      new_issue.project = self
       # Reassign fixed_versions by name, since names are unique per
       # project and the versions for self are not yet saved
       if issue.fixed_version
@@ -570,6 +573,13 @@ class Project < ActiveRecord::Base
       if issue.category
         new_issue.category = self.issue_categories.select {|c| c.name == issue.category.name}.first
       end
+      # Parent issue
+      if issue.parent_id
+        if copied_parent = issues_map[issue.parent_id]
+          new_issue.parent_issue_id = copied_parent.id
+        end
+      end
+      
       self.issues << new_issue
       issues_map[issue.id] = new_issue
     end
diff --git a/app/views/issues/_attributes.rhtml b/app/views/issues/_attributes.rhtml
index acbd9101a..455eb77b2 100644
--- a/app/views/issues/_attributes.rhtml
+++ b/app/views/issues/_attributes.rhtml
@@ -7,7 +7,7 @@
 <p><label><%= l(:field_status) %></label> <%= @issue.status.name %></p>
 <% end %>
 
-<p><%= f.select :priority_id, (@priorities.collect {|p| [p.name, p.id]}), :required => true %></p>
+<p><%= f.select :priority_id, (@priorities.collect {|p| [p.name, p.id]}), {:required => true}, :disabled => !@issue.leaf? %></p>
 <p><%= f.select :assigned_to_id, (@issue.assignable_users.collect {|m| [m.name, m.id]}), :include_blank => true %></p>
 <% unless @project.issue_categories.empty? %>
 <p><%= f.select :category_id, (@project.issue_categories.collect {|c| [c.name, c.id]}), :include_blank => true %>
@@ -31,10 +31,10 @@
 </div>
 
 <div class="splitcontentright">
-<p><%= f.text_field :start_date, :size => 10 %><%= calendar_for('issue_start_date') %></p>
-<p><%= f.text_field :due_date, :size => 10 %><%= calendar_for('issue_due_date') %></p>
-<p><%= f.text_field :estimated_hours, :size => 3 %> <%= l(:field_hours) %></p>
-<% if Issue.use_field_for_done_ratio? %>
+<p><%= f.text_field :start_date, :size => 10, :disabled => !@issue.leaf? %><%= calendar_for('issue_start_date') if @issue.leaf? %></p>
+<p><%= f.text_field :due_date, :size => 10, :disabled => !@issue.leaf? %><%= calendar_for('issue_due_date') if @issue.leaf? %></p>
+<p><%= f.text_field :estimated_hours, :size => 3, :disabled => !@issue.leaf? %> <%= l(:field_hours) %></p>
+<% if @issue.leaf? && Issue.use_field_for_done_ratio? %>
 <p><%= f.select :done_ratio, ((0..10).to_a.collect {|r| ["#{r*10} %", r*10] }) %></p>
 <% end %>
 </div>
diff --git a/app/views/issues/_form.rhtml b/app/views/issues/_form.rhtml
index 032d08205..72fd6221d 100644
--- a/app/views/issues/_form.rhtml
+++ b/app/views/issues/_form.rhtml
@@ -5,6 +5,16 @@
                                      :with => "Form.serialize('issue-form')" %>
 
 <p><%= f.text_field :subject, :size => 80, :required => true %></p>
+                                     
+<% unless (@issue.new_record? && @issue.parent_issue_id.nil?) || !User.current.allowed_to?(:manage_subtasks, @project) %>
+<p><%= f.text_field :parent_issue_id, :size => 10 %></p>
+<div id="parent_issue_candidates" class="autocomplete"></div>
+<%= javascript_tag "observeParentIssueField('#{url_for(:controller => :issues,
+                                                       :action => :auto_complete,
+                                                       :id => @issue,
+                                                       :project_id => @project) }')" %>
+<% end %>
+
 <p><%= f.text_area :description,
                    :cols => 60,
                    :rows => (@issue.description.blank? ? 10 : [[10, @issue.description.length / 50].max, 100].min),
diff --git a/app/views/issues/auto_complete.html.erb b/app/views/issues/auto_complete.html.erb
new file mode 100644
index 000000000..b130159eb
--- /dev/null
+++ b/app/views/issues/auto_complete.html.erb
@@ -0,0 +1,9 @@
+<ul>
+<% if @issues.any? -%>
+  <% @issues.each do |issue| -%>
+    <%= content_tag 'li', h("#{issue.tracker} ##{issue.id}: #{issue.subject}"), :id => issue.id %>
+  <% end -%>
+<% else -%>
+  <%= content_tag("li", l(:label_none), :style => 'display:none') %>
+<% end -%>
+</ul>
diff --git a/app/views/issues/gantt.rhtml b/app/views/issues/gantt.rhtml
index 8d6677d9c..f0c6f4622 100644
--- a/app/views/issues/gantt.rhtml
+++ b/app/views/issues/gantt.rhtml
@@ -79,8 +79,10 @@ t_height = g_height + headers_height
 # Tasks subjects
 #
 top = headers_height + 8
-@gantt.events.each do |i| %>
-    <div style="position: absolute;line-height:1.2em;height:16px;top:<%= top %>px;left:4px;overflow:hidden;"><small>    
+@gantt.events.each do |i|
+left = 4 + (i.is_a?(Issue) ? i.level * 16 : 0)
+ %>
+    <div style="position: absolute;line-height:1.2em;height:16px;top:<%= top %>px;left:<%= left %>px;overflow:hidden;"><small>    
     <% if i.is_a? Issue %>
       	<%= h("#{i.project} -") unless @project && @project == i.project %>
       	<%= link_to_issue i %>
@@ -189,15 +191,16 @@ top = headers_height + 10
 	i_width = ((i_end_date - i_start_date + 1)*zoom).floor - 2                  # total width of the issue (- 2 for left and right borders)
 	d_width = ((i_done_date - i_start_date)*zoom).floor - 2                     # done width
 	l_width = i_late_date ? ((i_late_date - i_start_date+1)*zoom).floor - 2 : 0 # delay width
+  css = "task " + (i.leaf? ? 'leaf' : 'parent')
 	%>
-	<div style="top:<%= top %>px;left:<%= i_left %>px;width:<%= i_width %>px;" class="task task_todo">&nbsp;</div>
+	<div style="top:<%= top %>px;left:<%= i_left %>px;width:<%= i_width %>px;" class="<%= css %> task_todo"><div class="left"></div>&nbsp;<div class="right"></div></div>
 	<% if l_width > 0 %>
-	    <div style="top:<%= top %>px;left:<%= i_left %>px;width:<%= l_width %>px;" class="task task_late">&nbsp;</div>
+	    <div style="top:<%= top %>px;left:<%= i_left %>px;width:<%= l_width %>px;" class="<%= css %> task_late">&nbsp;</div>
 	<% end %>
 	<% if d_width > 0 %>
-	    <div style="top:<%= top %>px;left:<%= i_left %>px;width:<%= d_width %>px;" class="task task_done">&nbsp;</div>
+	    <div style="top:<%= top %>px;left:<%= i_left %>px;width:<%= d_width %>px;" class="<%= css %> task_done">&nbsp;</div>
 	<% end %>
-	<div style="top:<%= top %>px;left:<%= i_left + i_width + 5 %>px;background:#fff;" class="task">
+	<div style="top:<%= top %>px;left:<%= i_left + i_width + 8 %>px;background:#fff;" class="<%= css %>">
 	<%= i.status.name %>
 	<%= (i.done_ratio).to_i %>%
 	</div>
diff --git a/app/views/issues/show.rhtml b/app/views/issues/show.rhtml
index b78908b00..c07fa921b 100644
--- a/app/views/issues/show.rhtml
+++ b/app/views/issues/show.rhtml
@@ -4,7 +4,10 @@
 
 <div class="<%= @issue.css_classes %> details">
         <%= avatar(@issue.author, :size => "50") %>
-        <h3><%=h @issue.subject %></h3>
+      
+<div class="subject">      
+<%= render_issue_subject_with_tree(@issue) %>
+</div>
         <p class="author">
         <%= authoring @issue.created_on, @issue.author %>.
         <% if @issue.created_on != @issue.updated_on %>
@@ -56,6 +59,17 @@
 
 <%= call_hook(:view_issues_show_description_bottom, :issue => @issue) %>
 
+<% if !@issue.leaf? || User.current.allowed_to?(:manage_subtasks, @project) %>
+<hr />
+<div id="issue_tree">
+<div class="contextual">
+  <%= link_to(l(:button_add), {:controller => 'issues', :action => 'new', :project_id => @project, :issue => {:parent_issue_id => @issue}}) if User.current.allowed_to?(:manage_subtasks, @project) %>
+</div>
+<p><strong><%=l(:label_subtask_pural)%></strong></p>
+<%= render_descendants_tree(@issue) unless @issue.leaf? %>
+</div>
+<% end %>
+
 <% if authorize_for('issue_relations', 'new') || @issue.relations.any? %>
 <hr />
 <div id="relations">
@@ -113,4 +127,8 @@
 <% content_for :header_tags do %>
     <%= auto_discovery_link_tag(:atom, {:format => 'atom', :key => User.current.rss_key}, :title => "#{@issue.project} - #{@issue.tracker} ##{@issue.id}: #{@issue.subject}") %>
     <%= stylesheet_link_tag 'scm' %>
+    <%= javascript_include_tag 'context_menu' %>
+    <%= stylesheet_link_tag 'context_menu' %>
 <% end %>
+<div id="context-menu" style="display: none;"></div>
+<%= javascript_tag "new ContextMenu('#{url_for(:controller => 'issues', :action => 'context_menu')}')" %>
\ No newline at end of file