Problem with integer radio custom field with 0 value

Actually when form is submitted and if radio is not selected than field with 0 value get saved in DB.

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When trying to verify ( http://issues.civicrm.org/jira/browse/CRM-4601 ), I created a custom group with (among others) an integer radio field with 0 and 1 options (both values and labels). When I edit a contact's custom data, this field is set to 0 even if no option is chosen.

This is most probably due to QuickForm's conflating of zero and null (no value). If so, you can try side-stepping it the same way as I did in CRM/Contact/Form/Merge.php (the $_qfZeroBug variable).