delete invited users when removed from project

app/controllers/members_controller.rb

@@ -117,8 +117,13 @@ class MembersController < ApplicationController
 
   def destroy
     if @member.deletable?
-      @member.destroy
-      flash.notice = l(:notice_member_removed)
+      if @member.disposable?
+        @member.user.destroy
+        flash.notice = I18n.t(:notice_member_removed)
+      else
+        @member.destroy
+        flash.notice = I18n.t(:notice_member_removed)
+      end
     end
 
     redirect_to project_members_path(project_id: @project)

app/models/member.rb

@@ -130,6 +130,13 @@ class Member < ActiveRecord::Base
     @membership
   end
 
+  ##
+  # Returns true if this user can be deleted as they have no other memberships
+  # and haven't been activated yet.
+  def disposable?
+    user.invited? && user.memberships.none? { |m| m.project_id != project_id }
+  end
+
   protected
 
   def destroy_if_no_roles_left!