Re: Boost.URL: Something Wicked This Way Comes!

From: Gavin Lambert (boost_at_[hidden])
Date: 2021-10-19 21:54:54

On 20/10/2021 02:12, Phil Endecott wrote:
> Right. But why has it chosen that goal, rather than the alternatives?
> What's the rationale?
> 
> It seems to me that a URL with redundant /s (e.g. 
> http://foo.com/path/////to/file)
> is either (a) malicious or erroneous input, or (b) equivalent to the
> versions without the redundant /s. So a user might want to (a) get  an
> exception or error, or (b) ignore the redundant segments. Under what
> circumstances would a user want to see the empty segments between those
> /s?

The rationale is the URI standard RFC.  It is not permitted for URI 
parsers to perform such collapsing because such URIs are entirely legal.

Unusual, certainly, especially for http[s] URIs that usually eventually 
end up at a filesystem that would collapse consecutive slashes.  Most 
web servers (regardless of whether evaluating vs a filesystem or not) 
will indeed collapse consecutive slashes too, at least while matching 
against resource rules.

But URIs are not required to wind up leading to a filesystem or to be 
served by a web server -- it's entirely possible that some other scheme 
may treat additional consecutive slashes as significant for some purpose.