[kupfer: 50/51] obj.base: Use _NonpersistentToken only if we have content to store

[Ulrik Sverdrup <usverdrup src gnome org>]

commit b2b2fec3f8817cb24e8ee6ce30f834633b56c5a5
Author: Ulrik Sverdrup <ulrik sverdrup gmail com>
Date:   Sun Jan 10 12:42:25 2010 +0100

    obj.base: Use _NonpersistentToken only if we have content to store

 kupfer/core/data.py |    2 +-
 kupfer/obj/base.py  |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/kupfer/core/data.py b/kupfer/core/data.py
index 7bd8a24..8a3d718 100644
--- a/kupfer/core/data.py
+++ b/kupfer/core/data.py
@@ -499,7 +499,7 @@ class SourceController (pretty.OutputMixin):
 		if hasattr(obj, "has_content"):
 			types = tuple(action.object_types()) if action else ()
 			contents = list(self.get_contents_for_leaf(obj, types))
-			content = contents and contents[0]
+			content = contents[0] if contents else None
 			if len(contents) > 1:
 				content = sources.SourcesSource(contents, name=unicode(obj),
 						use_reprs=False)
diff --git a/kupfer/obj/base.py b/kupfer/obj/base.py
index d877fb2..61ca5a7 100644
--- a/kupfer/obj/base.py
+++ b/kupfer/obj/base.py
@@ -174,7 +174,7 @@ class Leaf (KupferObject):
 
 	def add_content(self, content):
 		"""Register content source @content with Leaf"""
-		self._content_source = _NonpersistentToken(content)
+		self._content_source = content and _NonpersistentToken(content)
 
 	def has_content(self):
 		return self._content_source