From 9015b938cb2232c233a925e580b6a42f0066d08c Mon Sep 17 00:00:00 2001
From: Ronald Oussoren <ronaldoussoren@mac.com>
Date: Tue, 13 Jun 2006 11:19:56 +0000
Subject: [PATCH] Linecache contains support for PEP302 loaders, but fails to
 deal with loaders that return None to indicate that the module is valid but
 no source is available. This patch fixes that.

---
 Lib/linecache.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Lib/linecache.py b/Lib/linecache.py
index f49695ac1ce..4838625f08d 100644
--- a/Lib/linecache.py
+++ b/Lib/linecache.py
@@ -94,6 +94,10 @@ def updatecache(filename, module_globals=None):
                     except (ImportError, IOError):
                         pass
                     else:
+                        if data is None:
+                            # No luck, the PEP302 loader cannot find the source
+                            # for this module.
+                            return []
                         cache[filename] = (
                             len(data), None,
                             [line+'\n' for line in data.splitlines()], fullname