sampsyo/beets — pull request #965 by geigerzaehler (2014-09-17 10:21:55+00:00)
Title: Zero plugin can modify tags without changing the item

Code should be self explanatory. Should fix #963.

There is a possible issue with backwards compatibility: Changes to the item in the 'write' event do not propagate to the tags anymore. But I'm not aware of other plugins that use the API in that way.