From 2d8f26766870c79478b95200891aa10097c156af 2013-07-02 16:54:36
From: Puneeth Chaganti <punchagan@muse-amuse.in>
Date: 2013-07-02 16:54:36
Subject: [PATCH] Get Tracer working after ipapi.get replaced with get_ipython

Commit 790f731 replaced `ipapi.get` with a `get_ipython` function,
that changed the API slightly, returning None when no InteractiveShell
instance has been registered.

---

diff --git a/IPython/core/debugger.py b/IPython/core/debugger.py
index a4f908b..6b214a3 100644
--- a/IPython/core/debugger.py
+++ b/IPython/core/debugger.py
@@ -206,6 +206,12 @@ class Pdb(OldPdb):
 
         self.shell = get_ipython()
 
+        if self.shell is None:
+            # No IPython instance running, we must create one
+            from IPython.terminal.interactiveshell import \
+                TerminalInteractiveShell
+            self.shell = TerminalInteractiveShell.instance()
+
         if self.is_pydb:
 
             # interactiveshell.py's ipalias seems to want pdb's checkline