From d3db636b4c00893c857d228b91a28d7c85c4e7b4 2018-04-02 09:17:52
From: Thomas Kluyver <thomas@kluyver.me.uk>
Date: 2018-04-02 09:17:52
Subject: [PATCH] Allow offset 0 in position_to_cursor

Closes gh-11029

---

diff --git a/IPython/core/completer.py b/IPython/core/completer.py
index c84a586..cee7833 100644
--- a/IPython/core/completer.py
+++ b/IPython/core/completer.py
@@ -869,7 +869,7 @@ def position_to_cursor(text:str, offset:int)->Tuple[int, int]:
 
     """
 
-    assert 0 < offset <= len(text) , "0 < %s <= %s" % (offset , len(text))
+    assert 0 <= offset <= len(text) , "0 <= %s <= %s" % (offset , len(text))
 
     before = text[:offset]
     blines = before.split('\n')  # ! splitnes trim trailing \n