Fix to missing scheme handling (defaults to http)

[jonathon-love]

Fixes #619
Fixes #607

[cderv]

Thanks !
Two questions I have on this:

I am just wondering if we should assume that any parse url without scheme should be http. why not https ?

Also, I wonder if this type of fix (if scheme is null, assume http) should be better in request_perform directly.
I see parse_url as a utility function that helps get the pieces that compose a url. Currently, It could be used to know if a url as a scheme or not by testing if it returns null - with this fix, it can't. Do we want this change in httr::parse_url... 🤔

Just sharing thoughts to help decide what is best.

[jonathon-love]

I am just wondering if we should assume that any parse url without scheme should be http. why not https ?

the standard behaviour of web-browsers et al. is to default to http when no scheme is provided. and it would be consistent with the earlier versions of httr built against curl 3. (additionally, most https sites issue a redirect from http:// to https:// anyway)

Also, I wonder if this type of fix (if scheme is null, assume http) should be better in request_perform directly.

oh yeah, that's a fair point. i'll make that change.

with thanks

[hadley]

Can you please add a bullet to the top of NEWS.md? It should briefly describe the change and end with (@yourname, #issuenumber).

[petermeissner]

I have an issue reported in {robotstxt} directly related to this PR and also solved by this PR.

Will this PR be included in httr at some time in the future?

[hadley]

We don't have any plans to spin off a httr release at the moment.

[petermeissner]

Thanks, for the heads up.

[hadley]

httr has been superseded in favour of httr2, so is no longer under active development. Thanks for using httr, thanks for contributing, and my apologies that your contribution never made it into the package.