Today SegmentInfo doesn't know if it has vectors, which means its files() method must check if the files exist.
This leads to subtle bugs, because Si.files() caches the files but then we fail to invalidate that later when the term vectors files are created.
It also leads to sloppy code, eg TermVectorsReader "gracefully" handles being opened when the files do not exist. I don't like that; it should only be opened if they exist.
This also fixes these intermittent failures we've been seeing:
|Status||Open [ 1 ]||Resolved [ 5 ]|
|Resolution||Fixed [ 1 ]|
|Workflow||jira [ 12539970 ]||Default workflow, editable Closed status [ 12564206 ]|
|Workflow||Default workflow, editable Closed status [ 12564206 ]||jira [ 12585633 ]|
|Status||Resolved [ 5 ]||Closed [ 6 ]|