When joining to phone table in a contact record view, duplicate records encountered

To reproduce:

1. set up a contact record view
2. make sure some of your contacts have multiple phone numbers
3. add the phone field to the view

When I did this, I got a number of duplicates for each record equal to the number of phone numbers that contact had, even if I set it to filter by primary only.

After inspecting the actual query being run, I noticed that the civicrm_phone table was being joined to twice. I found the cause of this in civicrm_handler_field_phone.inc inside the ensure_my_table() method. I just commented it out and it fixed my problem. The line causing the issue is the one that says $join->extra ...

It looks like this method override was designed to make the phone type field option work so I wouldn't recommend just deleting it like I did.