From 529565862d131aee2009e7eb403870b87f14fb16 Mon Sep 17 00:00:00 2001
From: "Christian Y. Brenninkmeijer"
 <christian.brenninkmeijer@manchester.ac.uk>
Date: Thu, 28 Mar 2024 14:55:14 +0000
Subject: [PATCH] merged not equal routes are not defaultable

---
 spinn_machine/routing_entry.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/spinn_machine/routing_entry.py b/spinn_machine/routing_entry.py
index 1fddb82f..40dcc676 100644
--- a/spinn_machine/routing_entry.py
+++ b/spinn_machine/routing_entry.py
@@ -174,9 +174,11 @@ def merge(self, other: RoutingEntry) -> RoutingEntry:
             If the key and mask of the other entry do not match
         """
         # 2 different merged routes can NEVER be defaultable
+        if self == other:
+            return self
         return RoutingEntry(
             spinnaker_route=self.spinnaker_route | other.spinnaker_route,
-            defaultable=self.defaultable and other.defaultable)
+            defaultable=False)
 
     def __eq__(self, other_entry: Any) -> bool:
         if not isinstance(other_entry, RoutingEntry):