annotate relnotes/next @ 44893:95c832849955

setup: require that Python has TLS 1.1 or TLS 1.2

This ensures that Mercurial never downgrades the minimum TLS version from
TLS 1.1+ to TLS 1.0+ and enables us to remove that compatibility code.

It is reasonable to expect that distributions having Python 2.7.9+ or having
backported modern features to the ssl module (which we require) have a OpenSSL
version supporting TLS 1.1 or TLS 1.2, as this is the main reason why
distributions would want to backport these features.

TLS 1.1 and TLS 1.2 are often either both enabled or both not enabled.
However, both can be disabled independently, at least on current Python /
OpenSSL versions.

For the record, I contacted the CPython developers to remark that
unconditionally defining ssl.PROTOCOL_TLSv1_1 / ssl.PROTOCOL_TLSv1_2 is
problematic:
https://github.com/python/cpython/commit/6e8cda91d92da72800d891b2fc2073ecbc134d98#r39569316

== New Features ==


== New Experimental Features ==


== Backwards Compatibility Changes ==

* Mercurial now requires at least Python 2.7.9 or a Python version that
  backported modern SSL/TLS features (as defined in PEP 466), and that Python
  was compiled against a OpenSSL version supporting TLS 1.1 or TLS 1.2
  (likely this requires the OpenSSL version to be at least 1.0.1).


== Internal API Changes ==

 * logcmdutil.diffordiffstat() now takes contexts instead of nodes.

 * The `mergestate` class along with some related methods and constants have
   moved from `mercurial.merge` to a new `mercurial.mergestate` module.