FIX: close existing polls in closed topics to keep old behaviour

plugins/poll/db/migrate/20160321164925_close_polls_in_closed_topics.rb

@@ -0,0 +1,18 @@
+class ClosePollsInClosedTopics < ActiveRecord::Migration
+
+  def up
+    PostCustomField.joins(post: :topic)
+                   .where("post_custom_fields.name = 'polls'")
+                   .where("topics.closed")
+                   .find_each do |pcf|
+      polls = ::JSON.parse(pcf.value || "{}")
+      polls.values.each { |poll| poll["status"] = "closed" }
+      pcf.value = polls.to_json
+      pcf.save
+    end
+  end
+
+  def down
+  end
+
+end