bpo-39259: poplib now rejects timeout = 0 (GH-17912)
poplib.POP3 and poplib.POP3_SSL now raise a ValueError
if the given timeout for their constructor is zero to
prevent the creation of a non-blocking socket.
diff --git a/Doc/library/poplib.rst b/Doc/library/poplib.rst
index 28b42fa..2f349b3 100644
--- a/Doc/library/poplib.rst
+++ b/Doc/library/poplib.rst
@@ -47,6 +47,9 @@
``poplib.putline`` with arguments ``self`` and ``line``,
where ``line`` is the bytes about to be sent to the remote host.
+ .. versionchanged:: 3.9
+ If the *timeout* parameter is set to be zero, it will raise a
+ :class:`ValueError` to prevent the creation of a non-blocking socket.
.. class:: POP3_SSL(host, port=POP3_SSL_PORT, keyfile=None, certfile=None, timeout=None, context=None)
@@ -85,6 +88,10 @@
:func:`ssl.create_default_context` select the system's trusted CA
certificates for you.
+ .. versionchanged:: 3.9
+ If the *timeout* parameter is set to be zero, it will raise a
+ :class:`ValueError` to prevent the creation of a non-blocking socket.
+
One exception is defined as an attribute of the :mod:`poplib` module:
@@ -268,4 +275,3 @@
At the end of the module, there is a test section that contains a more extensive
example of usage.
-
diff --git a/Doc/whatsnew/3.9.rst b/Doc/whatsnew/3.9.rst
index ea6d8f5..3320b7c 100644
--- a/Doc/whatsnew/3.9.rst
+++ b/Doc/whatsnew/3.9.rst
@@ -187,6 +187,13 @@
:data:`os.P_PIDFD` (:issue:`38713`) for process management with file
descriptors.
+poplib
+------
+
+:class:`~poplib.POP3` and :class:`~poplib.POP3_SSL` now raise a :class:`ValueError`
+if the given timeout for their constructor is zero to prevent the creation of
+a non-blocking socket. (Contributed by Dong-hee Na in :issue:`39259`.)
+
threading
---------
diff --git a/Lib/poplib.py b/Lib/poplib.py
index 0b6750d..0f85873 100644
--- a/Lib/poplib.py
+++ b/Lib/poplib.py
@@ -107,6 +107,8 @@
self.welcome = self._getresp()
def _create_socket(self, timeout):
+ if timeout is not None and not timeout:
+ raise ValueError('Non-blocking socket (timeout=0) is not supported')
return socket.create_connection((self.host, self.port), timeout)
def _putline(self, line):
diff --git a/Lib/test/test_poplib.py b/Lib/test/test_poplib.py
index 911cba1..7f06d19 100644
--- a/Lib/test/test_poplib.py
+++ b/Lib/test/test_poplib.py
@@ -481,7 +481,7 @@
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.settimeout(60) # Safety net. Look issue 11812
self.port = test_support.bind_port(self.sock)
- self.thread = threading.Thread(target=self.server, args=(self.evt,self.sock))
+ self.thread = threading.Thread(target=self.server, args=(self.evt, self.sock))
self.thread.daemon = True
self.thread.start()
self.evt.wait()
@@ -505,12 +505,12 @@
def testTimeoutDefault(self):
self.assertIsNone(socket.getdefaulttimeout())
- socket.setdefaulttimeout(30)
+ socket.setdefaulttimeout(test_support.LOOPBACK_TIMEOUT)
try:
pop = poplib.POP3(HOST, self.port)
finally:
socket.setdefaulttimeout(None)
- self.assertEqual(pop.sock.gettimeout(), 30)
+ self.assertEqual(pop.sock.gettimeout(), test_support.LOOPBACK_TIMEOUT)
pop.close()
def testTimeoutNone(self):
@@ -524,9 +524,11 @@
pop.close()
def testTimeoutValue(self):
- pop = poplib.POP3(HOST, self.port, timeout=30)
- self.assertEqual(pop.sock.gettimeout(), 30)
+ pop = poplib.POP3(HOST, self.port, timeout=test_support.LOOPBACK_TIMEOUT)
+ self.assertEqual(pop.sock.gettimeout(), test_support.LOOPBACK_TIMEOUT)
pop.close()
+ with self.assertRaises(ValueError):
+ poplib.POP3(HOST, self.port, timeout=0)
def test_main():
diff --git a/Misc/NEWS.d/next/Library/2020-01-09-10-58-58.bpo-39259.RmDgCC.rst b/Misc/NEWS.d/next/Library/2020-01-09-10-58-58.bpo-39259.RmDgCC.rst
new file mode 100644
index 0000000..c7ef8be
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-01-09-10-58-58.bpo-39259.RmDgCC.rst
@@ -0,0 +1,3 @@
+:class:`~poplib.POP3` and :class:`~poplib.POP3_SSL` now raise a
+:class:`ValueError` if the given timeout for their constructor is zero to
+prevent the creation of a non-blocking socket. Patch by Dong-hee Na.