[Python-checkins] bpo-44359: Fix test_ftplib unhandled thread exceptions (GH-31069)

[miss-islington]

https://github.com/python/cpython/commit/0371e5d7f1248abb0712fc98c3135d01d265cec8
commit: 0371e5d7f1248abb0712fc98c3135d01d265cec8
branch: 3.9
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2022-02-01T18:16:58-08:00
summary:

bpo-44359: Fix test_ftplib unhandled thread exceptions (GH-31069)


test_ftplib now silently ignores socket errors to prevent logging
unhandled threading exceptions.
(cherry picked from commit 0611eafc709cbe8a2a0bdde082d25df0c5034de7)

Co-authored-by: Victor Stinner <vstinner at python.org>

files:
A Misc/NEWS.d/next/Tests/2022-02-02-02-24-04.bpo-44359.kPPSmN.rst
M Lib/test/test_ftplib.py

diff --git a/Lib/test/test_ftplib.py b/Lib/test/test_ftplib.py
index 6f8f977b3950d..b51e5440800cd 100644
--- a/Lib/test/test_ftplib.py
+++ b/Lib/test/test_ftplib.py
@@ -49,6 +49,13 @@
              "type=file;perm=r;unique==SGP2; file \xAE non-ascii char\r\n")
 
 
+def default_error_handler():
+    # bpo-44359: Silently ignore socket errors. Such errors occur when a client
+    # socket is closed, in TestFTPClass.tearDown() and makepasv() tests, and
+    # the server gets an error on its side.
+    pass
+
+
 class DummyDTPHandler(asynchat.async_chat):
     dtp_conn_closed = False
 
@@ -80,7 +87,7 @@ def push(self, what):
         super(DummyDTPHandler, self).push(what.encode(self.encoding))
 
     def handle_error(self):
-        raise Exception
+        default_error_handler()
 
 
 class DummyFTPHandler(asynchat.async_chat):
@@ -130,7 +137,7 @@ def found_terminator(self):
             self.push('550 command "%s" not understood.' %cmd)
 
     def handle_error(self):
-        raise Exception
+        default_error_handler()
 
     def push(self, data):
         asynchat.async_chat.push(self, data.encode(self.encoding) + b'\r\n')
@@ -308,7 +315,7 @@ def writable(self):
         return 0
 
     def handle_error(self):
-        raise Exception
+        default_error_handler()
 
 
 if ssl is not None:
@@ -411,7 +418,7 @@ def recv(self, buffer_size):
                 raise
 
         def handle_error(self):
-            raise Exception
+            default_error_handler()
 
         def close(self):
             if (isinstance(self.socket, ssl.SSLSocket) and
diff --git a/Misc/NEWS.d/next/Tests/2022-02-02-02-24-04.bpo-44359.kPPSmN.rst b/Misc/NEWS.d/next/Tests/2022-02-02-02-24-04.bpo-44359.kPPSmN.rst
new file mode 100644
index 0000000000000..00c29b1ca4089
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2022-02-02-02-24-04.bpo-44359.kPPSmN.rst
@@ -0,0 +1,2 @@
+test_ftplib now silently ignores socket errors to prevent logging unhandled
+threading exceptions. Patch by Victor Stinner.