Workhorse puts more constraints on complete multipart upload ETag than required
This is in reference to gitlab-ce#58511.
The multipart upload code when it issues the complete request makes an assumption on the format of the ETag in the response. It assumes it is an md5 hash of all the constituent part md5sums. According to the AWS S3 API on this request though, the ETag is opaque and does not have a formula or computation.
See the ETag field on the CompleteMultiPartUploadResult in the api.