poor urllib error handling

[gvanrossum]

BPO	1593751
Nosy	@gvanrossum, @birkenfeld

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2007-03-14.08:30:39.000>
created_at = <Date 2006-11-09.21:04:07.000>
labels = []
title = 'poor urllib error handling'
updated_at = <Date 2007-03-14.08:30:39.000>
user = 'https://github.com/gvanrossum'

bugs.python.org fields:

activity = <Date 2007-03-14.08:30:39.000>
actor = 'georg.brandl'
assignee = 'none'
closed = True
closed_date = None
closer = None
components = ['None']
creation = <Date 2006-11-09.21:04:07.000>
creator = 'gvanrossum'
dependencies = []
files = []
hgrepos = []
issue_num = 1593751
keywords = []
message_count = 4.0
messages = ['30498', '30499', '30500', '30501']
nosy_count = 4.0
nosy_names = ['gvanrossum', 'georg.brandl', 'racarr', 'robertwinder']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1593751'
versions = []

[gvanrossum]

I set up a simple server that returns an empty response.

>>> from socket import *
>>> s = socket()
>>> s.bind(("", 9999))
>>> while 1: x, c = s.accept(); print c; x.recv(1000);
x.close()
...

Pointing urllib at this gives a traceback:

Python 2.6a0 (trunk:52099M, Oct  3 2006, 09:59:17) 
[GCC 4.0.3 (Ubuntu 4.0.3-1ubuntu5)] on linux2
Type "help", "copyright", "credits" or "license" for
more information.
>>> import urllib
>>> urllib.urlopen('http://localhost:9999/')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/guido/p/Lib/urllib.py", line 82, in urlopen
    return opener.open(url)
  File "/home/guido/p/Lib/urllib.py", line 190, in open
    return getattr(self, name)(url)
  File "/home/guido/p/Lib/urllib.py", line 334, in
open_http
    return self.http_error(url, fp, errcode, errmsg,
headers)
  File "/home/guido/p/Lib/urllib.py", line 351, in
http_error
    return self.http_error_default(url, fp, errcode,
errmsg, headers)
  File "/home/guido/p/Lib/urllib.py", line 608, in
http_error_default
    return addinfourl(fp, headers, "http:" + url)
  File "/home/guido/p/Lib/urllib.py", line 951, in __init__
    addbase.__init__(self, fp)
  File "/home/guido/p/Lib/urllib.py", line 898, in __init__
    self.read = self.fp.read
AttributeError: 'NoneType' object has no attribute 'read'
>>> 

I can repeat this with 2.2.3 and 2.4.3 as well (don't
have 2.3 around for testing).

The direct cause of the problem is that h.getfile() on
line 329 of urllib.py (in head of trunk) returns None.

[racarr]

Fix?

Index: urllib.py
===================================================================
--- urllib.py (revision 52918)
+++ urllib.py (working copy)
@@ -895,8 +895,10 @@

     def __init__(self, fp):
         self.fp = fp
-        self.read = self.fp.read
-        self.readline = self.fp.readline
+       try:
+               self.read = self.fp.read
+               self.readline = self.fp.readline
+       except: print "File handler is none"
         if hasattr(self.fp, "readlines"): self.readlines = self.fp.readlines
         if hasattr(self.fp, "fileno"):
             self.fileno = self.fp.fileno

[robertwinder]

Same error handling with 2.3. Suggested fix doesn't work and gives.

AttributeError: addinfourl instance has no attribute 'read'

[birkenfeld]

Finally fixed in rev. 54376, 54377 (2.5).