From 9deb416e023396617928cb68b4629dc17a95cf6a 2013-02-12 23:59:00
From: y-p <yoval@gmx.com>
Date: 2013-02-12 23:59:00
Subject: [PATCH] Don't die if stderr/stdout do not support set_parent() #2925

If the user redirects the streams to a file for example,
the kernel would raise an exception because file
objects do not have set_parent defined, unlike ipython's
OutStream.
This happens even if the user does this in a spawned thread.

---

diff --git a/IPython/kernel/zmq/ipkernel.py b/IPython/kernel/zmq/ipkernel.py
index b010143..d69ef9c 100755
--- a/IPython/kernel/zmq/ipkernel.py
+++ b/IPython/kernel/zmq/ipkernel.py
@@ -364,8 +364,14 @@ class Kernel(Configurable):
         shell.displayhook.set_parent(parent)
         shell.display_pub.set_parent(parent)
         shell.data_pub.set_parent(parent)
-        sys.stdout.set_parent(parent)
-        sys.stderr.set_parent(parent)
+        try:
+            sys.stdout.set_parent(parent)
+        except AttributeError:
+            pass
+        try:
+            sys.stderr.set_parent(parent)
+        except AttributeError:
+            pass
 
         # Re-broadcast our input for the benefit of listening clients, and
         # start computing output
@@ -567,14 +573,20 @@ class Kernel(Configurable):
             return
 
         self._publish_status(u'busy', parent)
-        
+
         # Set the parent message of the display hook and out streams.
         shell = self.shell
         shell.displayhook.set_parent(parent)
         shell.display_pub.set_parent(parent)
         shell.data_pub.set_parent(parent)
-        sys.stdout.set_parent(parent)
-        sys.stderr.set_parent(parent)
+        try:
+            sys.stdout.set_parent(parent)
+        except AttributeError:
+            pass
+        try:
+            sys.stderr.set_parent(parent)
+        except AttributeError:
+            pass
 
         # pyin_msg = self.session.msg(u'pyin',{u'code':code}, parent=parent)
         # self.iopub_socket.send(pyin_msg)