Replaces "Create merge request" link with one to the MR when one exists

2 files changed, 20 insertions, 6 deletions

diff --git a/app/controllers/projects/commits_controller.rb b/app/controllers/projects/commits_controller.rb
index bf5b54c8cb7..1420b96840c 100644
--- a/app/controllers/projects/commits_controller.rb
+++ b/app/controllers/projects/commits_controller.rb
@@ -21,6 +21,9 @@ class Projects::CommitsController < Projects::ApplicationController
     @note_counts = project.notes.where(commit_id: @commits.map(&:id)).
       group(:commit_id).count
 
+    @merge_request = @project.merge_requests.opened.
+      find_by(source_project: @project, source_branch: @ref, target_branch: @repository.root_ref)
+
     respond_to do |format|
       format.html
       format.json { pager_json("projects/commits/_commits", @commits.size) }
diff --git a/app/controllers/projects/compare_controller.rb b/app/controllers/projects/compare_controller.rb
index 7bbe75b3974..dc5d217f3e4 100644
--- a/app/controllers/projects/compare_controller.rb
+++ b/app/controllers/projects/compare_controller.rb
@@ -4,24 +4,23 @@ class Projects::CompareController < Projects::ApplicationController
   # Authorize
   before_action :require_non_empty_project
   before_action :authorize_download_code!
+  before_action :assign_ref_vars, only: [:index, :show]
+  before_action :merge_request, only: [:index, :show]
 
   def index
-    @ref = Addressable::URI.unescape(params[:to])
   end
 
   def show
-    base_ref = Addressable::URI.unescape(params[:from])
-    @ref = head_ref = Addressable::URI.unescape(params[:to])
     diff_options = { ignore_whitespace_change: true } if params[:w] == '1'
 
     compare_result = CompareService.new.
-      execute(@project, head_ref, @project, base_ref, diff_options)
+      execute(@project, @head_ref, @project, @base_ref, diff_options)
 
     if compare_result
       @commits = Commit.decorate(compare_result.commits, @project)
       @diffs = compare_result.diffs
-      @commit = @project.commit(head_ref)
-      @base_commit = @project.merge_base_commit(base_ref, head_ref)
+      @commit = @project.commit(@head_ref)
+      @base_commit = @project.merge_base_commit(@base_ref, @head_ref)
       @diff_refs = [@base_commit, @commit]
       @line_notes = []
     end
@@ -31,4 +30,16 @@ class Projects::CompareController < Projects::ApplicationController
     redirect_to namespace_project_compare_path(@project.namespace, @project,
                                                params[:from], params[:to])
   end
+
+  private
+
+  def assign_ref_vars
+    @base_ref = Addressable::URI.unescape(params[:from])
+    @ref = @head_ref = Addressable::URI.unescape(params[:to])
+  end
+
+  def merge_request
+    @merge_request ||= @project.merge_requests.opened.
+      find_by(source_project: @project, source_branch: @head_ref, target_branch: @base_ref)
+  end
 end