Issue 24332: urllib.parse should not discard delimiters when associated component is empty

The documenatation for urllib.parse (https://docs.python.org/3.0/library/urllib.parse.html) states several times:

"This may result in a slightly different, but equivalent URL, if the URL that was parsed originally had unnecessary delimiters (for example, a ? with an empty query; the RFC states that these are equivalent)."

This is false -- RFC 3986 explicitly states that ? with an empty query is _not_ equivalent to a URL without it.  For example, the following two URL's should be considered different:

http://example.com/?
http://example.com/

https://tools.ietf.org/html/rfc3986#section-6.2.3

This is essentially the same as Issue 22852. The title just refers to stripping an empty #fragment, but the netloc and query components are also affected. I have a patch there which needs reviewing, if you are interested. Or if you have any alternative ideas on how to solve this they would be welcome too.

superseder: urllib.parse wrongly strips empty #fragment, ?query, //netloc

nosy: + martin.panter
messages: + msg244515
resolution: duplicate
stage: resolved