Add system note with link to diff comparison when MR discussion becomes outdated

2 files changed, 33 insertions, 1 deletions

diff --git a/db/migrate/20170521184006_add_change_position_to_notes.rb b/db/migrate/20170521184006_add_change_position_to_notes.rb
new file mode 100644
index 00000000000..0b199dade25
--- /dev/null
+++ b/db/migrate/20170521184006_add_change_position_to_notes.rb
@@ -0,0 +1,31 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddChangePositionToNotes < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  # When a migration requires downtime you **must** uncomment the following
+  # constant and define a short and easy to understand explanation as to why the
+  # migration requires downtime.
+  # DOWNTIME_REASON = ''
+
+  # When using the methods "add_concurrent_index", "remove_concurrent_index" or
+  # "add_column_with_default" you must disable the use of transactions
+  # as these methods can not run in an existing transaction.
+  # When using "add_concurrent_index" or "remove_concurrent_index" methods make sure
+  # that either of them is the _only_ method called in the migration,
+  # any other changes should go in a separate migration.
+  # This ensures that upon failure _only_ the index creation or removing fails
+  # and can be retried or reverted easily.
+  #
+  # To disable transactions uncomment the following line and remove these
+  # comments:
+  # disable_ddl_transaction!
+
+  def change
+    add_column :notes, :change_position, :text
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index d14126401c9..84e25427d7f 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170518231126) do
+ActiveRecord::Schema.define(version: 20170521184006) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -794,6 +794,7 @@ ActiveRecord::Schema.define(version: 20170518231126) do
     t.string "discussion_id"
     t.text "note_html"
     t.integer "cached_markdown_version"
+    t.text "change_position"
   end
 
   add_index "notes", ["author_id"], name: "index_notes_on_author_id", using: :btree