Add latest changes from gitlab-org/gitlab@master

app/services/members/create_service.rb

@@ -5,6 +5,7 @@ module Members
     BlankInvitesError = Class.new(StandardError)
     TooManyInvitesError = Class.new(StandardError)
     MembershipLockedError = Class.new(StandardError)
+    SeatLimitExceededError = Class.new(StandardError)
 
     DEFAULT_INVITE_LIMIT = 100
 
@@ -37,13 +38,13 @@ module Members
       publish_event!
 
       result
-    rescue BlankInvitesError, TooManyInvitesError, MembershipLockedError => e
+    rescue BlankInvitesError, TooManyInvitesError, MembershipLockedError, SeatLimitExceededError => e
       Gitlab::ErrorTracking.log_exception(e, class: self.class.to_s, user_id: current_user.id)
       error(e.message)
     end
 
     def single_member
-      members.last
+      members&.last
     end
 
     private

lib/api/helpers/members_helpers.rb

@@ -101,7 +101,7 @@ module API
 
         # prefer responding with model validations, if present
         member = instance.single_member
-        render_validation_error!(member) if member.invalid?
+        render_validation_error!(member) if member&.invalid?
 
         # if errors occurred besides model validations or authorization failures,
         # render those appropriately

locale/gitlab.pot

@@ -3094,6 +3094,9 @@ msgstr ""
 msgid "AddMember|No users specified."
 msgstr ""
 
+msgid "AddMember|Not enough seats for this many users."
+msgstr ""
+
 msgid "AddMember|Too many users specified (limit is %{user_limit})"
 msgstr ""