From a1bb5eda39e0990a2f854899d257ba4bbcae252e Mon Sep 17 00:00:00 2001
From: Neil Williams <neil@reddit.com>
Date: Sun, 3 Jun 2012 17:18:43 -0700
Subject: [PATCH] query_cache: Gracefully handle zero-query merge.

---
 r2/r2/models/query_cache.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/r2/r2/models/query_cache.py b/r2/r2/models/query_cache.py
index 35d99cdc5..bb9bb84ce 100644
--- a/r2/r2/models/query_cache.py
+++ b/r2/r2/models/query_cache.py
@@ -183,8 +183,11 @@ class MergedCachedQuery(CachedQueryBase):
     def __init__(self, queries):
         self.queries = queries
 
-        sort = queries[0].sort
-        assert all(sort == q.sort for q in queries)
+        if queries:
+            sort = queries[0].sort
+            assert all(sort == q.sort for q in queries)
+        else:
+            sort = []
         super(MergedCachedQuery, self).__init__(sort)
 
     def _fetch(self):