2 files changed, 5 insertions, 1 deletions
diff --git a/apt/cache.py b/apt/cache.py
index 384afe31..bbf2165b 100644
--- a/apt/cache.py
+++ b/apt/cache.py
@@ -101,6 +101,9 @@ class Cache(object):
     def has_key(self, key):
         return self._dict.has_key(key)
 
+    def __contains__(self, key):
+        return key in self._dict
+
     def __len__(self):
         return len(self._dict)
 
diff --git a/apt/package.py b/apt/package.py
index 096b1bd1..c1c2b1e1 100644
--- a/apt/package.py
+++ b/apt/package.py
@@ -186,7 +186,8 @@ class Package(object):
     def sourcePackageName(self):
         """ Return the source package name as string """
         if not self._lookupRecord():
-            return None
+            if not self._lookupRecord(UseCandidate=False):
+                return self._pkg.Name
         src = self._records.SourcePkg
         if src != "":
             return src