tree 65a9c7f9e7d068214ad36db434f4598bdc09500b
parent e92beb50a31e428406412fc4b55be4621addded4
author Jim Ferenczi <jim.ferenczi@elastic.co> 1585915085 +0200
committer jimczi <jim.ferenczi@elastic.co> 1585915536 +0200

LUCENE-9300: Fix field infos update on doc values update (#1394)

Today a doc values update creates a new field infos file that contains the original field infos updated for the new generation as well as the new fields created by the doc values update.

However existing fields are cloned through the global fields (shared in the index writer) instead of the local ones (present in the segment).
In practice this is not an issue since field numbers are shared between segments created by the same index writer.
But this assumption doesn't hold for segments created by different writers and added through IndexWriter#addIndexes(Directory).
In this case, the field number of the same field can differ between segments so any doc values update can corrupt the index
by assigning the wrong field number to an existing field in the next generation.

When this happens, queries and merges can access wrong fields without throwing any error, leading to a silent corruption in the index.

This change ensures that we preserve local field numbers when creating
a new field infos generation.