Allow merges from parents to children

app/controllers/projects/merge_requests_controller.rb

@@ -157,7 +157,13 @@ def ci_status
   protected
 
   def selected_target_project
-    ((@project.id.to_s == params[:target_project_id]) || @project.forked_project_link.nil?) ? @project : @project.forked_project_link.forked_from_project
+    if @project.id.to_s == params[:target_project_id]
+      @project
+    elsif @project.forked_from_project && @project.forked_from_project.id.to_s == params[:target_project_id]
+      @project.forked_from_project
+    else
+      Project.forked_to(@project).find {|proj|proj.id.to_s == params[:target_project_id]}
+    end
   end
 
   def merge_request

app/models/project.rb

@@ -118,6 +118,7 @@ class Project < ActiveRecord::Base
   scope :public_or_internal_only, ->(user) { where("visibility_level IN (:levels)", levels: user ? [ INTERNAL, PUBLIC ] : [ PUBLIC ]) }
 
   scope :non_archived, -> { where(archived: false) }
+  scope :forked_to, ->(project) { joins(:forked_project_link).where("forked_project_links.forked_from_project_id = ?", project.id)}
 
   enumerize :issues_tracker, in: (Gitlab.config.issues_tracker.keys).append(:gitlab), default: :gitlab
 
@@ -413,6 +414,18 @@ def forked?
     !(forked_project_link.nil? || forked_project_link.forked_from_project.nil?)
   end
 
+  def forked_to?
+    !(Project.forked_to(self)).empty?
+  end
+
+  def mergeable_to
+    projects = []
+    projects << self
+    projects << forked_from_project if forked?
+    projects = projects + Project.forked_to(self) if forked_to?
+    projects
+  end
+
   def personal?
     !group
   end

app/views/projects/merge_requests/_form.html.haml

@@ -21,8 +21,7 @@
       .span5
         .clearfix
           .pull-left
-            - projects =  @project.forked_from_project.nil? ? [@project] : [ @project,@project.forked_from_project]
-            = f.select(:target_project_id, options_from_collection_for_select(projects, 'id', 'path_with_namespace'), {}, { class: 'target_project chosen span3', disabled: @merge_request.persisted? })
+            = f.select(:target_project_id, options_from_collection_for_select(projects.mergable_to, 'id', 'path_with_namespace'), {}, { class: 'target_project chosen span3', disabled: @merge_request.persisted? })
           .pull-left
              
             = f.select(:target_branch, @target_branches, { include_blank: "Select branch" }, {class: 'target_branch chosen span2'})

features/project/forked_merge_requests.feature

@@ -32,3 +32,10 @@ Feature: Project Forked Merge Requests
     And I fill out an invalid "Merge Request On Forked Project" merge request
     And I submit the merge request
     Then I should see validation errors
+
+  @javascript
+  Scenario: I submit new unassigned merge request to a to forked project
+    Given I click "New Merge Request" button from "Shop" merge requests page
+    And I fill out a "Merge Request To Forked Project" merge request
+    And I submit the merge request
+    Then I should see merge request "Merge Request To Forked Project"

features/steps/project/project_forked_merge_requests.rb

@@ -139,7 +139,6 @@ class ProjectForkedMergeRequests < Spinach::FeatureSteps
     )
   end
 
-
   step 'I click link edit "Merge Request On Forked Project"' do
     find("#edit_merge_request").click
   end
@@ -171,6 +170,43 @@ class ProjectForkedMergeRequests < Spinach::FeatureSteps
     page.should have_content "Branch conflict You can not use same project/branch for source and target"
   end
 
+  step 'I click "New Merge Request" button from "Shop" merge requests page' do
+    @project.team.truncate
+    @project.team << [@user, :developer]
+    visit project_merge_requests_path(@project)
+    click_link "New Merge Request"
+  end
+
+  step 'I fill out a "Merge Request To Forked Project" merge request' do
+    chosen @project.id, from: "#merge_request_source_project_id"
+    chosen @forked_project.id, from: "#merge_request_target_project_id"
+
+    find(:select, "merge_request_source_project_id", {}).value.should == @project.id.to_s
+    find(:select, "merge_request_target_project_id", {}).value.should == @forked_project.id.to_s
+
+    chosen "stable", from: "#merge_request_source_branch"
+    chosen "master", from: "#merge_request_target_branch"
+
+    find(:select, "merge_request_source_branch", {}).value.should == 'stable'
+    find(:select, "merge_request_target_branch", {}).value.should == 'master'
+
+    fill_in "merge_request_title", with: "Merge Request To Forked Project"
+  end
+
+  step 'I should see merge request "Merge Request To Forked Project"' do
+    @forked_project.merge_requests.size.should >= 1
+    @merge_request = @forked_project.merge_requests.last
+    current_path.should == project_merge_request_path(@forked_project, @merge_request)
+    @merge_request.title.should == "Merge Request To Forked Project"
+    @merge_request.source_project.should == @project
+    @merge_request.source_branch.should == "stable"
+    @merge_request.target_branch.should == "master"
+    page.should have_content @forked_project.path_with_namespace
+    page.should have_content @project.path_with_namespace
+    page.should have_content @merge_request.source_branch
+    page.should have_content @merge_request.target_branch
+  end
+
   def project
     @project ||= Project.find_by_name!("Shop")
   end