From 73306c6fedd134e2d97f351c1bf1e657945771f7 Mon Sep 17 00:00:00 2001
From: "zhaozhao.zz" <zhaozhao.zz@alibaba-inc.com>
Date: Mon, 16 Jul 2018 20:48:07 +0800
Subject: [PATCH] Streams: correctly propagate xdel if needed

---
 src/t_stream.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/t_stream.c b/src/t_stream.c
index 44251586..3b4ebea7 100644
--- a/src/t_stream.c
+++ b/src/t_stream.c
@@ -2137,9 +2137,13 @@ void xdelCommand(client *c) {
         streamParseIDOrReply(c,c->argv[j],&id,0); /* Retval already checked. */
         deleted += streamDeleteItem(s,&id);
     }
-    signalModifiedKey(c->db,c->argv[1]);
-    notifyKeyspaceEvent(NOTIFY_STREAM,"xdel",c->argv[1],c->db->id);
-    server.dirty += deleted;
+
+    /* Propagate the write if needed. */
+    if (deleted) {
+        signalModifiedKey(c->db,c->argv[1]);
+        notifyKeyspaceEvent(NOTIFY_STREAM,"xdel",c->argv[1],c->db->id);
+        server.dirty += deleted;
+    }
     addReplyLongLong(c,deleted);
 }