[New-bugs-announce] [issue36372] Flawed handling of URL redirect

[Brrr Grrr]

New submission from Brrr Grrr <ab16180 at gmail.com>:

I'm unable to use `urlopen` to open 'https://www.annemergmed.com/article/S0196-0644(99)70271-4/abstract' with Python 3.7. I believe this to be flawed URL redirection, possibly due to flawed URL parsing.

```python
from sys import version
version
'3.7.2 (default, Dec 25 2018, 03:50:46) \n[GCC 7.3.0]'
from urllib.request import urlopen
urlopen('https://www.annemergmed.com/article/S0196-0644(99)70271-4/abstract')
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/usr/lib/python3.7/urllib/request.py", line 222, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 755, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/usr/lib/python3.7/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python3.7/urllib/request.py", line 563, in error
    result = self._call_chain(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.7/urllib/request.py", line 745, in http_error_302
    self.inf_msg + msg, headers, fp)
urllib.error.HTTPError: HTTP Error 302: The HTTP server returned a redirect error that would lead to an infinite loop.
The last 30x error message was:
Found
```

----------
components: IO
messages: 338404
nosy: bugburger
priority: normal
severity: normal
status: open
title: Flawed handling of URL redirect
type: crash
versions: Python 3.7

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue36372>
_______________________________________