From 80dca097eb9a9112d3630ff00b7f7d4c452b8f80 2016-03-08 12:45:23
From: Min RK <benjaminrk@gmail.com>
Date: 2016-03-08 12:45:23
Subject: [PATCH] Merge pull request #9306 from takluyver/doctest-traceback-terminal-size

Override terminal size in doctests to standardise traceback format
---

diff --git a/IPython/testing/plugin/ipdoctest.py b/IPython/testing/plugin/ipdoctest.py
index 015937b..baebc8b 100644
--- a/IPython/testing/plugin/ipdoctest.py
+++ b/IPython/testing/plugin/ipdoctest.py
@@ -28,6 +28,8 @@ import sys
 import traceback
 import unittest
 
+from testpath import modified_env
+
 from inspect import getmodule
 
 # We are overriding the default doctest runner, so we need to import a few
@@ -587,8 +589,10 @@ class IPDocTestRunner(doctest.DocTestRunner,object):
 
         test.globs.update(_ip.user_ns)
 
-        return super(IPDocTestRunner,self).run(test,
-                                               compileflags,out,clear_globs)
+        # Override terminal size to standardise traceback format
+        with modified_env({'COLUMNS': '80', 'LINES': '24'}):
+            return super(IPDocTestRunner,self).run(test,
+                                                   compileflags,out,clear_globs)
 
 
 class DocFileCase(doctest.DocFileCase):