From 62d11a71592cc5b273bf1e9e330cc59944639b06 2016-02-20 22:55:40
From: Dmitry Zotikov <xio@ungrund.org>
Date: 2016-02-20 22:55:40
Subject: [PATCH] Ensure pager interprets escape sequences

If less is specified in $PAGER, but $LESS either doesn't exist or doesn't contain `-r` option, append `-r` to the pager command string.
---

diff --git a/IPython/core/page.py b/IPython/core/page.py
index 35677d3..340d703 100644
--- a/IPython/core/page.py
+++ b/IPython/core/page.py
@@ -308,6 +308,13 @@ def get_pager_cmd(pager_cmd=None):
             pager_cmd = os.environ['PAGER']
         except:
             pager_cmd = default_pager_cmd
+    
+    if pager_cmd == 'less':
+    try:
+        os.getenv('LESS').index('-r')
+    except (ValueError, AttributeError):
+        pager_cmd += ' -r'
+    
     return pager_cmd