Based on patch by Guido van Rossum.

Initial patch from Xiang Zhang. Also fix out-of-date _url_collapse_path() doc
string.

Patch from Xiang Zhang.

Patch from Chiu-Hsiang Hsu.

robust at shutdown. If needs to release multiple resources, they are released
even if errors are occured.

Some http servers will reject PUT, POST, and PATCH requests if they
do not have a Content-Length header.

Patch by James Rutherford, with additional cleaning up of the
'request' documentation by me.

This changeset does two things: introduces a new RemoteDisconnected exception
(that subclasses ConnectionResetError and BadStatusLine) so that a remote
server disconnection can be detected by client code (and provides a better
error message for debugging purposes), and ensures that the client socket is
closed if a ConnectionError happens, so that the automatic re-connection code
can work if the application handles the error and continues on.

Tests are added that confirm that a connection is re-used or not re-used
as appropriate to the various combinations of protocol version and headers.

Patch by Martin Panter, reviewed by Demian Brecht.  (Tweaked only slightly by
me.)

Also deprecate the undocumented set argument instead of removing
it already in 3.5.

Initial patch by Demian Brecht.

broken after converting instance attributes to properies in issue #2211.

Setting attributes key, value and coded_value directly now is deprecated.
update() and setdefault() now transform and check keys.  Comparing for
equality now takes into account attributes key, value and coded_value.
copy() now returns a Morsel, not a dict.  repr() now contains all attributes.
Optimized checking keys and quoting values.  Added new tests.
Original patch by Demian Brecht.

Patch by Demian Brecht.

Original patch by Demian Brecht.

not as stringified enum.  Patch by Demian Brecht.

with the constants in http.client.

Initial patch by Demian Brecht.

Also, document the LineTooLong exception since it can be raised by
the members of public API (e.g. http.client.HTTPResponse).

Patch by Martin Panter.

document the requestline and close_connection attributes, use real booleans, and add tests (closes #23410)

Patch by Martin Panter.

Patch by Martin Panter.

Patch by Demian Brecht.

Patch by Demian Brecht.

This commit also removes a couple of non-standard status codes. They were
added as part of edf669b13482, so there is no backwards compatibility issue.

Patch by Demian Brecht.

Patch by Jon Dufresne.

Patch by Karan Goel.

HTTPStatus.NOT_FOUND).  Patch by Demian Brecht.

value in the host header was set to "None".  Patch by Demian Brecht.

HTTPSConnection: prefer the context's check_hostname attribute over the constructor parameter (#22959)

Original patch by Martin Panter.

Patch by Donald Stufft.

Issue #22796: HTTP cookie parsing is now stricter, in order to protect against potential injection attacks.

Patch by Alex Gaynor with some modifications by me.

and above.  Patch by Tim Graham.

with non-standard cookie handling in some Web browsers.

Reported by Sergey Bobrov.