dch: make sure branch is always defined

This fixes a problem when running git-dch form a detached HEAD

diff --git a/gbp/scripts/dch.py b/gbp/scripts/dch.py
index 12eae36..9b73b24 100644 (file)
--- a/gbp/scripts/dch.py
+++ b/gbp/scripts/dch.py
@@ -271,6 +271,7 @@ def main(argv):
     until = 'HEAD'
     found_snapshot_header = False
     version_change = {}
+    branch = None
 
     try:
         parser = GbpOptionParserDebian(command=os.path.basename(argv[0]), prefix='',