Mass Dedupe Flip Selected Duplicates does nothing

When running a deduplication rule, if matches are found the search results page provides a number of buttons. One of these offers to "Flip Selected Duplicates", by which I assume that if I run through the list of found duplicates and select a number of them using the checkbox, I should then be able to flip the selected pairs of records such that what was the duplicate record (on the left hand side) becomes the 'original' record on the right hand side. However, in practice, this button appears to do nothing.

CRM-16865 mentions the fact that this button does nothing, but it's not clear form that issue whether it was fixed, or whether it was ignored. If the functionality is not going to be made available, the button should be removed.