test_socket fails on an android emulator running an x86 system image at API level 21.

======================================================================
ERROR: testGetServBy (test.test_socket.GeneralModuleTests)
----------------------------------------------------------------------

Traceback (most recent call last):
  File "/sdcard/org.bitbucket.pyona/lib/python3.6/test/test_socket.py", line 913, in testGetServBy
    port2 = socket.getservbyname(service)
OSError: service/proto not found

======================================================================
ERROR: testGetaddrinfo (test.test_socket.GeneralModuleTests)
----------------------------------------------------------------------

Traceback (most recent call last):
  File "/sdcard/org.bitbucket.pyona/lib/python3.6/test/test_socket.py", line 1240, in testGetaddrinfo
    socket.getaddrinfo(HOST, "http")
  File "/sdcard/org.bitbucket.pyona/lib/python3.6/socket.py", line 732, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno 9] servname not supported for ai_socktype

Ran 530 tests in 26.702s

FAILED (errors=2, skipped=75)
test test_socket failed
1 test failed:
test_socket
Total duration: 0:00:27

On android getservbyname(const char *NAME, const char *PROTO) returns NULL when PROTO is NULL:

root@generic_x86:/data/local/tmp # python
Python 3.6.0a0 (default:811ccdee6f87+, May  7 2016, 17:56:37) 
[GCC 4.9 20140827 (prerelease)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import socket
>>> socket.getservbyname('daytime', 'tcp')
13
>>> socket.getservbyname('daytime', 'udp')
13
>>> socket.getservbyname('daytime')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: service/proto not found
>>> 

On android socket.getaddrinfo() raises an exception when port is not a number:

>>> socket.getaddrinfo('127.0.0.1', 80)
[(<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('127.0.0.1', 80)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 80))]
>>> socket.getaddrinfo('127.0.0.1', 'http')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/sdcard/org.bitbucket.pyona/lib/python3.6/socket.py", line 732, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno 9] servname not supported for ai_socktype
>>>

testGetaddrinfo does not fail anymore on an emulator running an android-23-x86, i.e. Android 6.0 or API 23.

Problems with the socket module on Android:
API 21:
a) Both getservbyname() and getservbyport() fail when the optional 'protocolname' parameter is not set to 'tcp' or 'udp'.
b) getservbyname() fails when 'servicename' is set to 'http'.
getaddrinfo() fails either when:
c) 'port' is 'http'.
d) Or the optional 'type' is not set to socket.SOCK_STREAM or socket.SOCK_DGRAM and 'port' is a string.

API 23:
e) getservbyport() fails when the optional 'protocolname' parameter is not set to 'tcp' or 'udp'.

IMHO case b) and c) are difficult to fix.
For case d), one could use the Python implementation of getaddrinfo, but Android does not have the deprecated getipnodebyaddr(), so it is necessary to disable ipv6 in this case. Not sure if this is worth it.

This patch fixes the testGetServBy test for API 21 and 23 (fixing the cases a) and e) of my previous msg).

This patch fixes the testGetaddrinfo test for API 21 (the test runs fine on API 23):
The failing statement 'socket.getaddrinfo(HOST, "http")' in testGetaddrinfo does not test explicitly for "http" and for the absence of the optional 'type' parameter.
When is_android is True, the 'socket.getaddrinfo('127.0.0.1', "echo", type=socket.SOCK_DGRAM)' statement is run instead and the test is ok.

This patch simply skips the statements that fail on Android.

Entered https://code.google.com/p/android/issues/detail?id=226677 on the AOSP issue tracker.

New patch using support.less_than_android_api(level).

New patch using sys.getandroidapilevel().
getandroidapilevel() is only available in 3.7, so only 3.7 is being fixed.

New changeset 95140ff32239 by Xavier de Gaye in branch 'default':
Issue bpo-26936: Fix the test_socket failures on Android - getservbyname(),
https://hg.python.org/cpython/rev/95140ff32239