_yaml.py: Tweak node_get so it can handle indices=[]
diff --git a/buildstream/_yaml.py b/buildstream/_yaml.py
index 1512a3c..3c75b39 100644
--- a/buildstream/_yaml.py
+++ b/buildstream/_yaml.py
@@ -451,7 +451,7 @@
     assert type(node) is Node
 
     path = key
-    if indices is None:
+    if indices:
         if default_value is _sentinel:
             value = node[0].get(key, Node(default_value, None, 0, 0))
         else: