startAppendOnly() fixed to set server.appendonly to 0 if the start failed.

src/aof.c

@@ -44,7 +44,6 @@ void stopAppendOnly(void) {
 /* Called when the user switches from "appendonly no" to "appendonly yes"
  * at runtime using the CONFIG command. */
 int startAppendOnly(void) {
-    server.appendonly = 1;
     server.lastfsync = time(NULL);
     server.appendfd = open(server.appendfilename,O_WRONLY|O_APPEND|O_CREAT,0644);
     if (server.appendfd == -1) {
@@ -52,13 +51,13 @@ int startAppendOnly(void) {
         return REDIS_ERR;
     }
     if (rewriteAppendOnlyFileBackground() == REDIS_ERR) {
-        server.appendonly = 0;
         close(server.appendfd);
         redisLog(REDIS_WARNING,"Redis needs to enable the AOF but can't trigger a background AOF rewrite operation. Check the above logs for more info about the error.");
         return REDIS_ERR;
     }
     /* We correctly switched on AOF, now wait for the rerwite to be complete
      * in order to append data on disk. */
+    server.appendonly = 1;
     server.aof_wait_rewrite = 1;
     return REDIS_OK;
 }