Invalid/missing checksums in proxy repositories are cached forever

If an artifact or metadata file is retrieved through a proxy repository before it's checksum files have been published the invalid or missing checksums are cached until the associated file itself has been updated.

In the case of missing checksums this is recorded in the attributes file as:

"remote.no-sha1":"true"

For a release artifact this typically means that a missing checksum is never retrieved, since artifact update times default to infinite. For metadata the situation is not much better, the invalid/missing checksum will be cached until the next time the metadata file is updated.

Note:

• Will clean up need to be done to fix this issue in proxies or will it just fix itself?