HTTP server doesn't clear previous request data in keep-alive connection.

[Konstantin Alekseev]

Django 2.1.4 affected.
Commit that enabled keep-alive connections ​https://github.com/django/django/commit/934acf1126995f6e6ccba5947ec8f7561633c27f
Bug: if you make two requests in one keep-alive connection and first request posted data that wasn't read in the view
then on second request that data will be read alongside with first line of the new request.
As a result request.method will contain "..data from previous request...POST"

Pull request with test and possible fix ​https://github.com/django/django/pull/10732

[Xavier Fernandez]

Hello,

our Selenium tests were also affected by the same change (bisecting lead to ​https://github.com/django/django/commit/e1721ece485b35ab5543f134203a8a8ce9f31a7c which is ​https://github.com/django/django/commit/934acf1126995f6e6ccba5947ec8f7561633c27f).

Basically, the webdriver get(url) gets stuck for several hundred of seconds leading to test timeout, I'm trying to build a minimal selenium test showing this regression.
In the meanwhile, the provided patch makes our tests pass again but seems to crash a bunch of threads with:

  File "/home/xfernandez/other_dev/django/django/core/servers/basehttp.py", line 101, in close
    obj._stream._read_limited()
AttributeError: '_io.BytesIO' object has no attribute '_read_limited'

or

  File "/home/xfernandez/other_dev/django/django/core/servers/basehttp.py", line 99, in close
    for obj in self.result._closable_objects:
AttributeError: 'FileWrapper' object has no attribute '_closable_objects'

[Xavier Fernandez]

Nevermind my previous comment, my issue was in fact different (and might actually be invalid), cf #30018

[Carlton Gibson <carlton.gibson@…>]

In b514dc14:

Fixed #30015 -- Ensured request body is properly consumed for keep-alive connections.

[Tim Graham <timograham@…>]

In bbe28fa0:

Refs #30015 -- Added 2.1.5 release note and removed 'we' in comments.

[Tim Graham <timograham@…>]

In 08f78a4f:

[2.1.x] Fixed #30015 -- Ensured request body is properly consumed for keep-alive connections.

Backport of b514dc14f4e1c364341f5931b354e83ef15ee12d and
bbe28fa07658f00786dc1d91ee281b4daac22d07 from master.