Merging tags results in duplicate tags on some entries

[tachyondecay]

Suppose an entry has the following tag list:

Clark Kent, Lois Lane, Superman, Jimmy Olsen

And then you decide to merge Clark Kent and Superman (for no particular reason). Then the entry’s tag list will look like so:

Clark Kent, Lois Lane, Clark Kent, Jimmy Olsen

This is because the merge operation doesn’t know with which entries a particular tag is associated with. All it cares about is updating all the tags with an old value to the new value, which results in a duplicate.

This isn’t a critical bug, because editing/saving the entry will get rid of the duplicate easily enough. The merge operation should do some kind of cleanup to prevent this from happening.