urllib3 LocationParseError uncaught by requests

[Arduous]

When accessing a page that is not redirecting properly (in this case, port is "-1", urllib3 LocationParseError is returned without being caught by requests.
The URL currently (Jul 23rd 2018) badly redirecting: https://www.fossil.com/us/en/account-dashboard/registered-products.html

Expected Result

An exception raised by requests, like InvalidURL

Actual Result

Exception from urllib3 is not masked

Reproduction Steps

import requests
test = requests.get("https://www.fossil.com/us/en/account-dashboard/registered-products.html")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/requests/api.py", line 72, in get
    return request('get', url, params=params, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/requests/api.py", line 58, in request
    return session.request(method=method, url=url, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 512, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 644, in send
    history = [resp for resp in gen] if allow_redirects else []
  File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 222, in resolve_redirects
    **adapter_kwargs
  File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 622, in send
    r = adapter.send(request, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/requests/adapters.py", line 410, in send
    conn = self.get_connection(request.url, proxies)
  File "/usr/local/lib/python2.7/dist-packages/requests/adapters.py", line 314, in get_connection
    conn = self.poolmanager.connection_from_url(url)
  File "/usr/local/lib/python2.7/dist-packages/urllib3/poolmanager.py", line 277, in connection_from_url
    u = parse_url(url)
  File "/usr/local/lib/python2.7/dist-packages/urllib3/util/url.py", line 199, in parse_url
    raise LocationParseError(url)
urllib3.exceptions.LocationParseError: Failed to parse: www.fossil.com:-1

System Information

$ python -m requests.help

{
  "chardet": {
    "version": "3.0.4"
  }, 
  "cryptography": {
    "version": "2.2.2"
  }, 
  "idna": {
    "version": "2.7"
  }, 
  "implementation": {
    "name": "CPython", 
    "version": "2.7.9"
  }, 
  "platform": {
    "release": "4.9.35-v7+", 
    "system": "Linux"
  }, 
  "pyOpenSSL": {
    "openssl_version": "1000114f", 
    "version": "18.0.0"
  }, 
  "requests": {
    "version": "2.19.1"
  }, 
  "system_ssl": {
    "version": "1000114f"
  }, 
  "urllib3": {
    "version": "1.23"
  }, 
  "using_pyopenssl": true
}

[nateprewitt]

Thanks for bringing this to our attention @Arduous! We do appear to be leaking an exception when we're trying to pull a connection from the pool. We should try to identify what exceptions can be raised here and then add handling for at least urllib3.exceptions.HTTPError, and possibly more specific cases if appropriate.

[nateprewitt]

Resolved with #4765.