Running flatten on a site with eZ Survey extension is use, will result in loss of data collected within these surveys.

This consequence can be inferred by the Known issue that resulted from https://jira.ez.no/browse/EZP-15413

Besides updating the Known issue to make this behavior clear, eZ Survey and / or flatten mechanism could be enhanced to solve the issue.

steps to reproduce

• Create eZSurvey object
• Answer to the survey
• Edit eZSurvey objet to obtain new version
• Answer to the survey
• Check your eZSurvey results
• Use flatten.php all
• Check your eZSurvey results