pgq.cascade.admin: do not allow subscribing to itself (same node)

diff --git a/python/pgq/cascade/admin.py b/python/pgq/cascade/admin.py
index ef2236575bc4c356956460807fb3ca7c1f6a1769..39ffd96cef1178e33b05e628e78779cbb987e55a 100644 (file)
--- a/python/pgq/cascade/admin.py
+++ b/python/pgq/cascade/admin.py
@@ -546,6 +546,9 @@ class CascadeAdmin(skytools.AdminScript):
         if not node or not consumer:
             node, consumer = self.find_consumer(node = node, consumer = consumer)
 
+        if node == new_provider:
+            raise UsageError ("cannot subscribe to itself")
+
         cmap = self.get_node_consumer_map(node)
         cinfo = cmap[consumer]
         old_provider = cinfo['provider_node']