cache and downloads

[hannesm]

I've a code question, while reading opamRepository.ml, in fetch_from_cache (I assumed this would take a file from a local cache), there's the following snippet:

  let dl_from_cache_job root_cache_url checksum file =
    let url = cache_url root_cache_url checksum in
    match url.OpamUrl.backend with
    | `http ->
      OpamDownload.download_as
        ~quiet:true ~validate:false ~overwrite:true ~checksum
        url file

this looks to me that it will call out to curl/wget, and taking that validate:false there will be no validation of the checksum. why?

I'd be interested in scenarios which fail if validate:true would be passed here.

[rjbou]

In all cases (local or http), checksums are validated afterwards, in the continuation if the download/copy succeed. And If no checksum is available, fetching from cache is not performed.

[hannesm]

thanks!