> nginx with merge_slashes
How can it be wrong if it is server-side? If the server wants to treat those paths equally, it can if it wants to.
It would only be wrong if a client does it and requests a different URL than the user entered, right?
It matters where the normalization happens, and server-side behavior is out-of-scope of these identifier RFCs.
> Therefore, collapsing // to / in HTTP URL path segments is not correct normalization. It produces a different, non-equivalent identifier unless the origin explicitly defines those two paths as equivalent.
It gets worse if you are mapping URLs to a filesystem (e.g. for serving files). Even though they look similar, URL paths have different capabilities and rules than filesystems, and different filesystems also vary. This is also an example of that (I don't think most filesystems support empty directory names).
Because maybe you use S3, which treats `foo/bar.txt` and `foo//bar.txt` as entirely separate things. Because to S3, directories don't exist and those are literally the exact names of the keys under which data is stored.
So you have script A concatenate "foo" + "/bar" and script B concatenate "foo/" + "/bar", and suddenly you have a weird problem.
I can't imagine a real use case where you'd think this is desirable.
Not S3, but here's a literal real use case: the entry for the Iraqw word /ameeni (woman) in Wiktionary.
https://en.wiktionary.org/wiki//ameeni
If for whatever reason your S3 keys contained English words and their translations separated by a slash, you would have a real problem if one of your scripts were to concatenate woman, / and /ameeni as woman/ameeni instead of woman//ameeni in the English/Iraqw case.
Nothing on web is "correct", deal with it
Of course you shouldn't assume that in a client. If you are implementing against an API don't deviate regarding // and trailing / from the API documentation.
Not doing it is like punishing people for not using Oxford commas, or entering an hour long debate each time someone writes “would of” instead of “would have”. It grinds my gears too, but I have different hills to die on.
Plenty of websites rewrite paths like /a/b/c/d into a backend service call like /?w=a&x=b&y=c&z=d. In that scheme, /a//c/d would rewrite to /?w=a&x=&y=c&z=d, something entirely distinct from /a/c/d working out to /?w=a&x=b&y=c
It's not the application's fault that the people attempting to configure web server URLs don't know how web server URLs work.
Not that you can include custom normalization rules (like collapsing slashes, tolower()ing the entire path, removing the query part of the URL), but that's not part of the standard. If you're doing anything extra, the risk of breaking stuff is on you.