Wrong search results for calculated fields

Currently when a field is calculated from sources other than the issue itself, Jira does not reindex the issue when the underlying values have changed. This leads to wrong search results.

In some cases, like the "last commenter" example in the docs, searching will work because a comment triggers a reindex of the issue, but most other calculated fields will also reference data that is held outside of the issue itself.

One example use cases is calculating an implicit due date from the due dates of the fix versions of that issue (see http://forums.atlassian.com/thread.jspa?threadID=8404&tstart=0). Currently when someone changes the version due date, the index would get out of sync.

There are many more use cases where searching calculated fields would be desirable and doesn't currently work:

• remote custom field like the Amazon search plugin from the tutorial
• fields that aggregate information from other issues (e.g. via following links)

Somehow a calculated field should be able to indicate which issues need a reindex before the field can be used as a search parameter, the default impl in CalculatedCFType would return an empty set.