[issue37405] socket.getsockname() returns string instead of tuple

New submission from Brent Gardner bggardner@gmail.com:
In Python 3.5.3, a socket with type AF_CAN returns a tuple in the form `(interface, )` from getsockname(). In Python 3.7.3, getsockname() returns a string (the name of the interface). The documentation states "a tuple is used for the AF_CAN address family". The string will break code that worked in 3.5.3 by raising errors such as "Value Error: too many values to unpack (expected 2)".
Example:
#3.5.3 import socket s = socket.socket(socket.AF_CAN, socket.SOCK_RAW, socket.CAN_RAW) s.bind(('vcan0',)) # requires tuple s.getsockname() # returns tuple: ('vcan0', 29)
#3.7.3 import socket s = socket.socket(socket.AF_CAN, socket.SOCK_RAW, socket.CAN_RAW) s.bind(('vcan0',)) # requires tuple s.getsockname() # returns string: 'vcan0'
---------- assignee: docs@python components: Documentation messages: 346559 nosy: Brent Gardner, docs@python priority: normal severity: normal status: open title: socket.getsockname() returns string instead of tuple versions: Python 3.7
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Change by Brent Gardner bggardner@gmail.com:
---------- type: -> behavior
_______________________________________ Python tracker report@bugs.python.org https://bugs.python.org/issue37405 _______________________________________

Brent Gardner bggardner@gmail.com added the comment:
Changed caused by commit effc12f8e9e20d0951d2ba5883587666bd8218e3 to cpython/Modules/socketmodule.c on Sep 6, 2017.
---------- components: +Extension Modules
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Brent Gardner bggardner@gmail.com added the comment:
Correction, change caused by a30f6d45ac3e72761b96a8df0527182029eaee24 to cpython/Modules/socketmodule.c on Aug 28, 2017.
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Change by Ned Deily nad@python.org:
---------- nosy: +christian.heimes
_______________________________________ Python tracker report@bugs.python.org https://bugs.python.org/issue37405 _______________________________________

Change by Roundup Robot devnull@psf.upfronthosting.co.za:
---------- keywords: +patch pull_requests: +14206 stage: -> patch review pull_request: https://github.com/python/cpython/pull/14392
_______________________________________ Python tracker report@bugs.python.org https://bugs.python.org/issue37405 _______________________________________

Benjamin Peterson benjamin@python.org added the comment:
New changeset 954900a3f98a8c0dea14dd575490237f3f8626b3 by Benjamin Peterson (bggardner) in branch 'master': closes bpo-37405: Make socket.getsockname() always return a tuple for AF_CAN. (GH-14392) https://github.com/python/cpython/commit/954900a3f98a8c0dea14dd575490237f3f8...
---------- nosy: +benjamin.peterson resolution: -> fixed stage: patch review -> resolved status: open -> closed
_______________________________________ Python tracker report@bugs.python.org https://bugs.python.org/issue37405 _______________________________________

Change by miss-islington mariatta.wijaya+miss-islington@gmail.com:
---------- pull_requests: +15641 pull_request: https://github.com/python/cpython/pull/16018
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Benjamin Peterson benjamin@python.org added the comment:
New changeset f60fd95dcc189ace8c0a2177a394b9cc20389a1e by Benjamin Peterson (Miss Islington (bot)) in branch '3.8': closes bpo-37405: Make socket.getsockname() always return a tuple for AF_CAN. (GH-14392) (GH-16018) https://github.com/python/cpython/commit/f60fd95dcc189ace8c0a2177a394b9cc203...
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FRANK BENNETT fbennett78@reagan.com added the comment:
$ make test TESTOPTS="-v test_socket"
ERROR: testSendFrame (__main__.CANTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/s/opt/cpython/debug/test_socket.py", line 2052, in testSendFrame self.assertEqual(addr[1], socket.AF_CAN) IndexError: tuple index out of range
$ cat ../.git/config https://github.com/bennett78/cpython.git
$ uname -r 5.4.0-67-genericg$ cat /etc/issue Ubuntu 20.04.2 LTS \n \l
$ /s/opt/cpython/debug$ ./python -V Python 3.10.0a6+
---------- components: +Tests -Documentation, Extension Modules nosy: +bennett78 versions: +Python 3.10 -Python 3.7
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Brent Gardner bggardner@gmail.com added the comment:
This test was overlooked, and line 2052 should now be removed per the discussion here:
https://github.com/python/cpython/pull/14392#issuecomment-506133908
In short, getsockname() used to return `(interface, socket.AF_CAN)`, in which the socket.AF_CAN element was superfluous (also undocumented), so it was removed in the fix, and the tuple format was reinstated.
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_______________________________________ Python tracker report@bugs.python.org https://bugs.python.org/issue37405 _______________________________________

Change by Brent Gardner bggardner@gmail.com:
---------- pull_requests: +23749 pull_request: https://github.com/python/cpython/pull/24991
_______________________________________ Python tracker report@bugs.python.org https://bugs.python.org/issue37405 _______________________________________
participants (6)
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Benjamin Peterson
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Brent Gardner
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FRANK BENNETT
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miss-islington
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Ned Deily
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Roundup Robot