change

app/controllers/pull_requests_controller.rb

@@ -155,11 +155,11 @@ class PullRequestsController < ApplicationController
       user_name_target = forked_source_project.owner.try(:login)
       git_target_tree = '--git-dir=/home/git/repositories/' + user_name_target + '/' + identifier + '.git'
       
-      git_sourse_commit_id = @g.commis(@project.gpid, :ref => source_branch).first.try(:id)
-      git_target_commit_id = @g.commis(forked_source_project.gpid, :ref => target_branch).first.try(:id)
+      git_sourse_commit_id = @g.commits(@project.gpid, :ref_name => source_branch).first.try(:id)
+      git_target_commit_id = @g.commits(forked_source_project.gpid, :ref_name => target_branch).first.try(:id)
     else
-      git_sourse_commit_id = @g.commis(@project.gpid, :ref => source_branch).first.try(:id)
-      git_target_commit_id = @g.commis(@project.gpid, :ref => target_branch).first.try(:id)
+      git_sourse_commit_id = @g.commits(@project.gpid, :ref_name => source_branch).first.try(:id)
+      git_target_commit_id = @g.commits(@project.gpid, :ref_name => target_branch).first.try(:id)
     end
     status = (git_sourse_commit_id ==  git_target_commit_id ? false : true)
   end