Defines Poll::Question#answerable_by?(user) and uses it in abilities

app/models/abilities/common.rb

@@ -49,7 +49,9 @@ module Abilities
         can :create, DirectMessage
         can :show, DirectMessage, sender_id: user.id
         can(:answer, Poll, Poll.current){ |poll| poll.current? }
-        can :answer, Poll::Question, geozones: {id: user.geozone_id}
+        can(:answer, Poll::Question, Poll::Question.answerable_by(user)) do |question|
+          question.answerable_by?(user)
+        end
       end
 
       can [:create, :show], ProposalNotification, proposal: { author_id: user.id }

app/models/poll/question.rb

@@ -46,6 +46,17 @@ class Poll::Question < ActiveRecord::Base
     end
   end
 
+  def answerable_by?(user)
+    user.present? && poll.current? && (self.all_geozones || self.geozone_ids.include?(user.geozone_id))
+  end
 
+  def self.answerable_by(user)
+    return where(false) unless user.present?
+    where(poll_id: Poll.current.pluck(:id))
+      .joins(:geozones)
+      .where('poll_questions.all_geozones = ? or geozones.id = ?',
+              true,
+              user.geozone_id || -1) # user.geozone_id can be nil, which would throw errors on sql
+  end
 
 end