bpo-32034: Make IncompleteReadError & LimitOverrunError pickleable GH-4409 (#4411)

(cherry picked from commit 43605e6bfa8d49612df4a38460d063d6ba781906)

3 files changed, 25 insertions, 0 deletions

diff --git a/Lib/asyncio/streams.py b/Lib/asyncio/streams.py
index a82cc79..4089b0e 100644
--- a/Lib/asyncio/streams.py
+++ b/Lib/asyncio/streams.py
@@ -35,6 +35,9 @@ class IncompleteReadError(EOFError):
         self.partial = partial
         self.expected = expected
 
+    def __reduce__(self):
+        return type(self), (self.partial, self.expected)
+
 
 class LimitOverrunError(Exception):
     """Reached the buffer limit while looking for a separator.
@@ -46,6 +49,9 @@ class LimitOverrunError(Exception):
         super().__init__(message)
         self.consumed = consumed
 
+    def __reduce__(self):
+        return type(self), (self.args[0], self.consumed)
+
 
 @coroutine
 def open_connection(host=None, port=None, *,
diff --git a/Lib/test/test_asyncio/test_streams.py b/Lib/test/test_asyncio/test_streams.py
index b47433a..6d16d20 100644
--- a/Lib/test/test_asyncio/test_streams.py
+++ b/Lib/test/test_asyncio/test_streams.py
@@ -3,6 +3,7 @@
 import gc
 import os
 import queue
+import pickle
 import socket
 import sys
 import threading
@@ -845,6 +846,23 @@ os.close(fd)
         stream._transport.__repr__.return_value = "<Transport>"
         self.assertEqual("<StreamReader t=<Transport>>", repr(stream))
 
+    def test_IncompleteReadError_pickleable(self):
+        e = asyncio.IncompleteReadError(b'abc', 10)
+        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+            with self.subTest(pickle_protocol=proto):
+                e2 = pickle.loads(pickle.dumps(e, protocol=proto))
+                self.assertEqual(str(e), str(e2))
+                self.assertEqual(e.partial, e2.partial)
+                self.assertEqual(e.expected, e2.expected)
+
+    def test_LimitOverrunError_pickleable(self):
+        e = asyncio.LimitOverrunError('message', 10)
+        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+            with self.subTest(pickle_protocol=proto):
+                e2 = pickle.loads(pickle.dumps(e, protocol=proto))
+                self.assertEqual(str(e), str(e2))
+                self.assertEqual(e.consumed, e2.consumed)
+
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/Misc/NEWS.d/next/Library/2017-11-15-13-44-28.bpo-32034.uHAOmu.rst b/Misc/NEWS.d/next/Library/2017-11-15-13-44-28.bpo-32034.uHAOmu.rst
new file mode 100644
index 0000000..828e8cd
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2017-11-15-13-44-28.bpo-32034.uHAOmu.rst
@@ -0,0 +1 @@
+Make asyncio.IncompleteReadError and LimitOverrunError pickleable.