Python RemoteDriver regression in version 3.14.0

[jugglinmike]

OS: macOS
Selenium Version: 3.14.0 (Python bindings)
Browser: Apple Safari
Browser Version: 11.1.1 (13605.2.8)

Expected Behavior -

The RemoteDriver should be capable of sending multiple commands to the same session.

Actual Behavior -

The RemoteDriver fails to interact with a session following creation.

Steps to reproduce -

Given a file repro.py:

from selenium import webdriver
driver = webdriver.Remote('http://127.0.0.1:4444')
driver.title

And a running instance of safaridriver via

$ safaridriver --port 4444

Version 3.13.0 executes the script with no errors. Version 3.14.0 reports the following error:

Traceback (most recent call last):
  File "repro.py", line 3, in <module>
    driver.title
  File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 341, in title
    resp = self.execute(Command.GET_TITLE)
  File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 320, in execute
    self.error_handler.check_response(response)
  File "/Library/Python/2.7/site-packages/selenium/webdriver/remote/errorhandler.py", line 208, in check_response
    raise exception_class(value)
selenium.common.exceptions.WebDriverException: Message: 

(The reported error message is truncated.)

[lmtierney]

It looks like safaridriver needs keep_alive set with the urllib3 changes (using webdriver.Safari() sets keep_alive to True by default). This works without error:

from selenium import webdriver
driver = webdriver.Remote('http://127.0.0.1:4444', keep_alive=True)
driver.title

I'm not sure what change with the move to urllib3 would have caused this to start happening though. @AutomatedTester thoughts?

[lmtierney]

It seems to work if I duplicate the conditional:

if body and method != 'POST' and method != 'PUT':
    body = None

To the non-keep_alive request

selenium/py/selenium/webdriver/remote/remote_connection.py

Lines 394 to 409 in 49a58eb

	if self.keep_alive:
	if body and method != 'POST' and method != 'PUT':
	body = None
	resp = self._conn.request(method, url, body=body, headers=headers)
	statuscode = resp.status
	else:
	http = urllib3.PoolManager()
	resp = http.request(method, url, body=body, headers=headers)
	statuscode = resp.status
	if not hasattr(resp, 'getheader'):
	if hasattr(resp.headers, 'getheader'):
	resp.getheader = lambda x: resp.headers.getheader(x)
	elif hasattr(resp.headers, 'get'):
	resp.getheader = lambda x: resp.headers.get(x)

[lmtierney]

Also of note... Tech Preview returns a w3c payload so you'll get different results if you use regular safaridriver vs TP

[jugglinmike]

I first experienced the regression using Safari Technology Preview, but I figured the report would seem more legitimate if it were demonstrated with more stable software :)

[jugglinmike]

Thanks, @AutomatedTester!