net/url: url.Parse decodes the Path portion of a URL

[gopherbot]

by stuart.carnie:

What does 'go version' print?

1.3

What steps reproduce the problem?
If possible, include a link to a program on play.golang.org.

http://play.golang.org/p/ZAdvTSBQm5

What happened?

The Path section of the URL has been decoded, which creates a new (and invalid).
server.com is expecting to find a file in "/images" called
"http%3A%2F%2Fdroplr.static.s3.amazonaws.com%2Fassets%2Femail%2Fimg%2Ftips-mac%2Ftips-mac-4.jpg"
not
"http://droplr.static.s3.amazonaws.com/assets/email/img/tips-mac/tips-mac-4.jpg";

What should have happened instead?

[ianlancetaylor]

Comment 1:

This is documented behaviour: http://golang.org/pkg/net/url/#URL .

Status changed to WorkingAsIntended.

[gopherbot]

Comment 2 by stuart.carnie:

I see that in the docs, however it simply documents a significant floor of the API. As a
consumer, it renders the http.(Get|Head|Post|PostForm) and http.NewRequest APIs
unreliable for a class of URLs that use encoded values in path segments.
As a workaround, I will need to write my own url parse function and set the URL.Opaque
property in order to allow requests with encoded path value to succeed.

[gopherbot]

Comment 3 by stuart.carnie:

Per RFC 3986, Section 7.3 Back-end Transcoding:
"Percent-encoded octets must be decoded at some point during the dereference process. 
Applications must split the URI into its components and subcomponents prior to decoding
the octets, as otherwise the decoded octets might be mistaken for delimiters."
http://tools.ietf.org/html/rfc3986#section-7.3
I'd interpret that as meaning the path must be separated into it's components, separated
by "/" and then decoded into an array OR if the path is retained as a string, it should
not be decoded at all

[gopherbot]

Comment 4 by stuart.carnie:

I'm resurrecting this issue, because the "documented behavior" to use Opaque is broken
in other scenarios…I'll log all the data in a follow up issue