Merge branch 'fix-merge-request-assignee-list' into 'master'

Use the user list from the target project in a merge request

### What does this MR do?

This MR derives the assignable users from the target project.

### Why was this MR needed?

In a merge request, the assignable users uses the list from the forked project, not the target project where the merge request will be going. For example, if I fork a project from the gitlab-org namespace into my personal namespace, make some changes, and then create a merge request, the only users I see are me. I think it makes more sense to show all the users in gitlab-org. This is a regression caused by 1c2711f7.

### What are the relevant issue numbers?

Closes #1535

See merge request !682

CHANGELOG

@@ -5,6 +5,7 @@ v 7.12.0 (unreleased)
   - Disabled expansion of top/bottom blobs for new file diffs
   - Update Asciidoctor gem to version 1.5.2. (Jakub Jirutka)
   - Fix resolving of relative links to repository files in AsciiDoc documents. (Jakub Jirutka)
+  - Use the user list from the target project in a merge request (Stan Hu)
 
 v 7.11.1
   - no changes

app/helpers/selects_helper.rb

@@ -10,6 +10,7 @@ module SelectsHelper
     any_user = opts[:any_user] || false
     email_user = opts[:email_user] || false
     first_user = opts[:first_user] && current_user ? current_user.username : false
+    project = opts[:project] || @project
 
     html = {
       class: css_class,
@@ -21,8 +22,8 @@ module SelectsHelper
     }
 
     unless opts[:scope] == :all
-      if @project
-        html['data-project-id'] = @project.id
+      if project
+        html['data-project-id'] = project.id
       elsif @group
         html['data-group-id'] = @group.id
       end

app/views/projects/_issuable_form.html.haml

@@ -46,7 +46,7 @@
     .col-sm-10
       = users_select_tag("#{issuable.class.model_name.param_key}[assignee_id]",
           placeholder: 'Select a user', class: 'custom-form-control', null_user: true,
-          selected: issuable.assignee_id)
+          selected: issuable.assignee_id, project: @target_project || @project)
        
       = link_to 'Assign to me', '#', class: 'btn assign-to-me-link'
 .form-group

app/views/projects/merge_requests/show/_context.html.haml

@@ -9,7 +9,7 @@
         none
     .issuable-context-selectbox
       - if can?(current_user, :modify_merge_request, @merge_request)
-        = users_select_tag('merge_request[assignee_id]', placeholder: 'Select assignee', class: 'custom-form-control js-select2 js-assignee', selected: @merge_request.assignee_id, null_user: true)
+        = users_select_tag('merge_request[assignee_id]', placeholder: 'Select assignee', class: 'custom-form-control js-select2 js-assignee', selected: @merge_request.assignee_id, project: @target_project, null_user: true)
 
   %div.prepend-top-20.clearfix
     .issuable-context-title

features/project/forked_merge_requests.feature

@@ -38,3 +38,15 @@ Feature: Project Forked Merge Requests
     Given I visit project "Forked Shop" merge requests page
     And I click link "New Merge Request"
     Then the target repository should be the original repository
+
+  @javascript
+  Scenario: I see the users in the target project for a new merge request
+    Given I logout
+    And I sign in as an admin
+    And I have a project forked off of "Shop" called "Forked Shop"
+    Then I visit project "Forked Shop" merge requests page
+    And I click link "New Merge Request"
+    And I fill out a "Merge Request On Forked Project" merge request
+    When I click "Assign to" dropdown"
+    Then I should see the target project ID in the input selector
+    And I should see the users from the target project ID

features/steps/project/forked_merge_requests.rb

@@ -128,6 +128,21 @@ class Spinach::Features::ProjectForkedMergeRequests < Spinach::FeatureSteps
     page.should have_select("merge_request_target_project_id", selected: @project.path_with_namespace)
   end
 
+  step 'I click "Assign to" dropdown"' do
+    first('.ajax-users-select').click
+  end
+
+  step 'I should see the target project ID in the input selector' do
+    expect(page).to have_selector("input[data-project-id=\"#{@project.id}\"]")
+  end
+
+  step 'I should see the users from the target project ID' do
+    expect(page).to have_selector('.user-result', visible: true, count: 2)
+    users = page.all('.user-name')
+    users[0].text.should == 'Unassigned'
+    users[1].text.should == @project.users.first.name
+  end
+
   # Verify a link is generated against the correct project
   def verify_commit_link(container_div, container_project)
     # This should force a wait for the javascript to execute