buildstream/_gitsourcebase.py: Fix return of get_ref() when no ref is available
That was causing invalid warning. Fixes #1020.
diff --git a/buildstream/_gitsourcebase.py b/buildstream/_gitsourcebase.py
index 7d07c56..38c844c 100644
--- a/buildstream/_gitsourcebase.py
+++ b/buildstream/_gitsourcebase.py
@@ -469,7 +469,10 @@
self.mirror.tags = self._load_tags(node)
def get_ref(self):
- return self.mirror.ref, self.mirror.tags
+ if self.mirror.ref:
+ return self.mirror.ref, self.mirror.tags
+ else:
+ return None
def set_ref(self, ref_data, node):
if not ref_data:
