From ca7b8dd163120aa75503039db7bedea78edee82a Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Tue, 26 Mar 2019 13:04:58 +0100
Subject: [PATCH 1/4] catch errors when writing on closed sockets

avoids issues with direct-checks for closed or closing sockets,
which seems to change across tornado versions

fixes some tornado 6 issues
---
 notebook/base/zmqhandlers.py | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/notebook/base/zmqhandlers.py b/notebook/base/zmqhandlers.py
index 7d0538fce..327fdd559 100644
--- a/notebook/base/zmqhandlers.py
+++ b/notebook/base/zmqhandlers.py
@@ -11,7 +11,8 @@ from urllib.parse import urlparse
 
 import tornado
 from tornado import gen, ioloop, web
-from tornado.websocket import WebSocketHandler
+from tornado.iostream import StreamClosedError
+from tornado.websocket import WebSocketHandler, WebSocketClosedError
 
 from jupyter_client.session import Session
 from jupyter_client.jsonutil import date_default, extract_dates
@@ -181,8 +182,13 @@ class WebSocketMixin(object):
             self.log.warning("WebSocket ping timeout after %i ms.", since_last_pong)
             self.close()
             return
+        try:
+            self.ping(b'')
+        except (StreamClosedError, WebSocketClosedError):
+            # websocket has been closed, stop pinging
+            self.ping_callback.stop()
+            return
 
-        self.ping(b'')
         self.last_ping = now
 
     def on_pong(self, data):
@@ -242,8 +248,14 @@ class ZMQStreamHandler(WebSocketMixin, WebSocketHandler):
             msg = self._reserialize_reply(msg_list, channel=channel)
         except Exception:
             self.log.critical("Malformed message: %r" % msg_list, exc_info=True)
-        else:
+            return
+
+        try:
             self.write_message(msg, binary=isinstance(msg, bytes))
+        except (StreamClosedError, WebSocketClosedError):
+            self.log.warning("zmq message arrived on closed channel")
+            self.close()
+            return
 
 
 class AuthenticatedZMQStreamHandler(ZMQStreamHandler, IPythonHandler):

From e908edf1714dff43a1646467190060cc5163a4db Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Tue, 26 Mar 2019 15:01:06 +0100
Subject: [PATCH 2/4] Fix return value for async restart_kernel

gen.Return shouldn't be passed the Future, the future should be awaited
---
 notebook/services/kernels/kernelmanager.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/notebook/services/kernels/kernelmanager.py b/notebook/services/kernels/kernelmanager.py
index fa52b5dfb..b072e014b 100644
--- a/notebook/services/kernels/kernelmanager.py
+++ b/notebook/services/kernels/kernelmanager.py
@@ -342,7 +342,8 @@ class MappingKernelManager(MultiKernelManager):
         channel.on_recv(on_reply)
         loop = IOLoop.current()
         timeout = loop.add_timeout(loop.time() + self.kernel_info_timeout, on_timeout)
-        raise gen.Return(future)
+        # wait for restart to complete
+        yield future
 
     def notify_connect(self, kernel_id):
         """Notice a new connection to a kernel"""

From a53733474465ec4a0ade8bf0a7780a913af09ed7 Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Tue, 26 Mar 2019 15:51:04 +0100
Subject: [PATCH 3/4] Changelog for 5.7.7

---
 docs/source/changelog.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/docs/source/changelog.rst b/docs/source/changelog.rst
index 42f5125b0..e54ee380e 100644
--- a/docs/source/changelog.rst
+++ b/docs/source/changelog.rst
@@ -21,6 +21,16 @@ We strongly recommend that you upgrade pip to version 9+ of pip before upgrading
     Use ``pip install pip --upgrade`` to upgrade pip. Check pip version with
     ``pip --version``.
 
+.. _release-5.7.7:
+
+5.7.7
+-----
+
+- Fix regression in restarting kernels in 5.7.5.
+  The restart handler would return before restart was completed.
+- Further improve compatibility with tornado 6 with improved
+  checks for when websockets are closed.
+
 .. _release-5.7.6:
 
 5.7.6

From 850eda5657f2afd63ad56d4f1dec3355bdb4a072 Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Wed, 27 Mar 2019 14:43:25 +0100
Subject: [PATCH 4/4] add .js mimetype fix to changelog

---
 docs/source/changelog.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/source/changelog.rst b/docs/source/changelog.rst
index e54ee380e..8e64a212f 100644
--- a/docs/source/changelog.rst
+++ b/docs/source/changelog.rst
@@ -30,6 +30,7 @@ We strongly recommend that you upgrade pip to version 9+ of pip before upgrading
   The restart handler would return before restart was completed.
 - Further improve compatibility with tornado 6 with improved
   checks for when websockets are closed.
+- Fix regression in 5.7.6 on Windows where .js files could have the wrong mime-type.
 
 .. _release-5.7.6: