Problem with partial responses (Content-Range)

[joliss]

Go's net/http/fs.go sets the Content-Range header based on offsets in the uncompressed files.

But the Content-Range header applies to entity-body (RFC 2616):

14.16 Content-Range

   The Content-Range entity-header is sent with a partial entity-body to
   specify where in the full entity-body the partial body should be
   applied.

And entity-body is defined as the gzipped stream:

       entity-body := Content-Encoding( Content-Type( data ) )

So I believe that if we try to apply gzip encoding transparently, partial responses will become garbled.

I haven't actually tested whether this is a problem, but since I just spent half an hour investigating the RFC, I figured I'd share this with you.

[daaku]

Ah, good to know. I'm not terribly familiar with how partial responses work, will try to write some test cases up and see what happens. Or feel free to send a pull request :)

[joliss]

Another problem might be ETags btw - I believe they may need to be different for the compressed and uncompressed resource. (All of this is trouble because the protocol is kinda broken when it comes to compression.)

[gsauthof]

Another problem might be ETags btw - I believe they may need to be different for the compressed and uncompressed resource.

One way to deal with that is to weaken the ETag.