From 2a7a2de84a6fbd11c0674dcd45439a994831a12d Mon Sep 17 00:00:00 2001
From: Andrey Smirnov <Smirnov.Andrey@gmail.com>
Date: Wed, 16 Jul 2014 02:23:55 +0400
Subject: [PATCH] Allow empty source in PackageList.Filter. #64

---
 deb/list.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/deb/list.go b/deb/list.go
index fbfd4946..8825b768 100644
--- a/deb/list.go
+++ b/deb/list.go
@@ -416,7 +416,9 @@ func (l *PackageList) Filter(queries []PackageQuery, withDependencies bool, sour
 		added := result.Len()
 
 		dependencySource := NewPackageList()
-		dependencySource.Append(source)
+		if source != nil {
+			dependencySource.Append(source)
+		}
 		dependencySource.Append(result)
 		dependencySource.PrepareIndex()