Poll doesn't erase vote results after editing

According to this Evgeniy's comment http://jira.jtalks.org/browse/JC-915?focusedCommentId=17031&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-17031 there is the bug with vote results.

How to reproduce-1:

1. Create a new poll with a few different variants.
2. Add a few votes for varied variants.
3. Open topic for editing and add one more variant. Save topic.

AR: The vote results after editing and before editing are equal.
ER: The vote results are empty.

How to reproduce-2:

1. Create a new poll with a few different variants.
2. Add a few votes for varied variants.
3. Open topic for editing and edit one variant with some votes. Save topic.

AR: The vote result for editing variant is empty, but another vote results are saved.
ER: The vote results are empty.