Querying for change returns the same change twice, with different states

[Daniele Sassoli]

Hi All,

I wanted to bring to your attention an issue that we've recently found for
installations using Lucene indexes. The issue report is at [1].

The issue we've observed is specific to the changes index. This index is
actually two separate indexes, "open" and "closed" changes.

When the status of a change changes, i.e. from open to merged, from open to
abandoned, etc..., changes are removed from the open index and added to the
closed index. If the deletion fails and someone queries for this change, it'll
be displayed twice, in two different states, open and closed, at the same
time!!!

This mechanism within Gerrit hasn't really changed over the last ~10 years, so
it appears weird that we only start seeing it now.

Has anyone encountered this issue and resolved it?

[1] https://issues.gerritcodereview.com/issues/440360427