From 85b363342c0d3a25155c500b42810f9ef9d82a22 Mon Sep 17 00:00:00 2001
From: Steve Baker <sbaker@redhat.com>
Date: Tue, 4 Jun 2013 17:25:42 +1200
Subject: [PATCH] For Fn::Join, replace None items with an empty string.

Currently, attempts to join lists with None items results in an error.

This change is required for the next attempt to fix bug: #1184794

Change-Id: Ib599eeb21b7325ff797768100f1556a424a8bde9
---
 heat/engine/template.py   | 9 ++++++++-
 heat/tests/test_parser.py | 4 ++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/heat/engine/template.py b/heat/engine/template.py
index 3bd77f31..bee3931a 100644
--- a/heat/engine/template.py
+++ b/heat/engine/template.py
@@ -217,7 +217,14 @@ class Template(collections.Mapping):
 
             if not isinstance(strings, (list, tuple)):
                 raise TypeError('Arguments to "Fn::Join" not fully resolved')
-            return delim.join(strings)
+
+            def empty_for_none(v):
+                if v is None:
+                    return ''
+                else:
+                    return v
+
+            return delim.join(empty_for_none(value) for value in strings)
 
         return _resolve(lambda k, v: k == 'Fn::Join', handle_join, s)
 
diff --git a/heat/tests/test_parser.py b/heat/tests/test_parser.py
index 5baa4c0f..55db0d0c 100644
--- a/heat/tests/test_parser.py
+++ b/heat/tests/test_parser.py
@@ -79,6 +79,10 @@ class ParserTest(HeatTestCase):
         raw = {'Fn::Join': [' ', ['foo', 'bar', 'baz']]}
         self.assertEqual(join(raw), 'foo bar baz')
 
+    def test_join_none(self):
+        raw = {'Fn::Join': [' ', ['foo', None, 'baz']]}
+        self.assertEqual(join(raw), 'foo  baz')
+
     def test_join_list(self):
         raw = [{'Fn::Join': [' ', ['foo', 'bar', 'baz']]}, 'blarg', 'wibble']
         parsed = join(raw)
-- 
2.45.2