X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/1824e3a3a37eb9618aa487e6e071395758bdaca8..a950a84303038d3365442a48cc2c06f4b5d3f65e:/src/replication.c

diff --git a/src/replication.c b/src/replication.c
index 479dcf43..e8297839 100644
--- a/src/replication.c
+++ b/src/replication.c
@@ -517,9 +517,23 @@ void slaveofCommand(redisClient *c) {
             redisLog(REDIS_NOTICE,"MASTER MODE enabled (user request)");
         }
     } else {
+        long port;
+
+        if ((getLongFromObjectOrReply(c, c->argv[2], &port, NULL) != REDIS_OK))
+            return;
+
+        /* Check if we are already attached to the specified slave */
+        if (server.masterhost && !strcasecmp(server.masterhost,c->argv[1]->ptr)
+            && server.masterport == port) {
+            redisLog(REDIS_NOTICE,"SLAVE OF would result into synchronization with the master we are already connected with. No operation performed.");
+            addReplySds(c,sdsnew("+OK Already connected to specified master\r\n"));
+            return;
+        }
+        /* There was no previous master or the user specified a different one,
+         * we can continue. */
         sdsfree(server.masterhost);
         server.masterhost = sdsdup(c->argv[1]->ptr);
-        server.masterport = atoi(c->argv[2]->ptr);
+        server.masterport = port;
         if (server.master) freeClient(server.master);
         if (server.repl_state == REDIS_REPL_TRANSFER)
             replicationAbortSyncTransfer();
@@ -582,7 +596,7 @@ void replicationCron(void) {
             if (slave->replstate == REDIS_REPL_SEND_BULK) continue;
             if (slave->replstate == REDIS_REPL_ONLINE) {
                 /* If the slave is online send a normal ping */
-                addReplySds(slave,sdsnew("PING\r\n"));
+                addReplySds(slave,sdsnew("*1\r\n$4\r\nPING\r\n"));
             } else {
                 /* Otherwise we are in the pre-synchronization stage.
                  * Just a newline will do the work of refreshing the