[1.6.x] Fixed "Address already in use" from liveserver.

Our WSGIServer rewrapped the socket errors from server_bind into
WSGIServerExceptions, which is used later on to provide nicer
error messages in runserver and used by the liveserver to see if
the port is already in use. But wrapping server_bind isn't enough since
it only binds to the socket, socket.listen (which is called from
server_activate) could also raise "Address already in use".

Instead of overriding server_activate too I chose to just catch socket
errors, which seems to make more sense anyways and should be more robust
against changes in wsgiref.

Backport of 2ca00faa91 from master.

django/core/management/commands/runserver.py

@@ -1,12 +1,13 @@
 from optparse import make_option
 from datetime import datetime
+import errno
 import os
 import re
 import sys
 import socket
 
 from django.core.management.base import BaseCommand, CommandError
-from django.core.servers.basehttp import run, WSGIServerException, get_internal_wsgi_application
+from django.core.servers.basehttp import run, get_internal_wsgi_application
 from django.utils import autoreload
 
 naiveip_re = re.compile(r"""^(?:
@@ -117,16 +118,16 @@ class Command(BaseCommand):
             handler = self.get_handler(*args, **options)
             run(self.addr, int(self.port), handler,
                 ipv6=self.use_ipv6, threading=threading)
-        except WSGIServerException as e:
+        except socket.error as e:
             # Use helpful error messages instead of ugly tracebacks.
             ERRORS = {
-                13: "You don't have permission to access that port.",
-                98: "That port is already in use.",
-                99: "That IP address can't be assigned-to.",
+                errno.EACCES: "You don't have permission to access that port.",
+                errno.EADDRINUSE: "That port is already in use.",
+                errno.EADDRNOTAVAIL: "That IP address can't be assigned-to.",
             }
             try:
-                error_text = ERRORS[e.args[0].args[0]]
-            except (AttributeError, KeyError):
+                error_text = ERRORS[e.errno]
+            except KeyError:
                 error_text = str(e)
             self.stderr.write("Error: %s" % error_text)
             # Need to use an OS exit because sys.exit doesn't work in a thread

django/core/servers/basehttp.py

@@ -58,10 +58,6 @@ def get_internal_wsgi_application():
     )
 
 
-class WSGIServerException(Exception):
-    pass
-
-
 class ServerHandler(simple_server.ServerHandler, object):
     error_status = str("500 INTERNAL SERVER ERROR")
 
@@ -114,10 +110,7 @@ class WSGIServer(simple_server.WSGIServer, object):
 
     def server_bind(self):
         """Override server_bind to store the server name."""
-        try:
-            super(WSGIServer, self).server_bind()
-        except Exception as e:
-            six.reraise(WSGIServerException, WSGIServerException(e), sys.exc_info()[2])
+        super(WSGIServer, self).server_bind()
         self.setup_environ()
 
 

django/test/testcases.py

@@ -7,6 +7,7 @@ from functools import wraps
 import json
 import os
 import re
+import socket
 import sys
 import select
 import socket
@@ -21,8 +22,7 @@ from django.core.handlers.wsgi import WSGIHandler
 from django.core.management import call_command
 from django.core.management.color import no_style
 from django.core.management.commands import flush
-from django.core.servers.basehttp import (WSGIRequestHandler, WSGIServer,
-    WSGIServerException)
+from django.core.servers.basehttp import WSGIRequestHandler, WSGIServer
 from django.core.urlresolvers import clear_url_caches, set_urlconf
 from django.db import connection, connections, DEFAULT_DB_ALIAS, transaction
 from django.db.models.loading import cache
@@ -1089,10 +1089,9 @@ class LiveServerThread(threading.Thread):
                 try:
                     self.httpd = StoppableWSGIServer(
                         (self.host, port), QuietWSGIRequestHandler)
-                except WSGIServerException as e:
+                except socket.error as e:
                     if (index + 1 < len(self.possible_ports) and
-                        hasattr(e.args[0], 'errno') and
-                        e.args[0].errno == errno.EADDRINUSE):
+                        e.errno == errno.EADDRINUSE):
                         # This port is already in use, so we go on and try with
                         # the next one in the list.
                         continue

tests/servers/tests.py

@@ -5,10 +5,10 @@ Tests for django.core.servers.
 from __future__ import unicode_literals
 
 import os
+import socket
 
 from django.core.exceptions import ImproperlyConfigured
 from django.test import LiveServerTestCase
-from django.core.servers.basehttp import WSGIServerException
 from django.test.utils import override_settings
 from django.utils.http import urlencode
 from django.utils.six.moves.urllib.error import HTTPError
@@ -71,7 +71,7 @@ class LiveServerAddress(LiveServerBase):
         cls.raises_exception('localhost', ImproperlyConfigured)
 
         # The host must be valid
-        cls.raises_exception('blahblahblah:8081', WSGIServerException)
+        cls.raises_exception('blahblahblah:8081', socket.error)
 
         # The list of ports must be in a valid format
         cls.raises_exception('localhost:8081,', ImproperlyConfigured)