Add comment explaining negative repeat

src/redis-cli.c

@@ -1141,6 +1141,8 @@ static int cliSendCommand(int argc, char **argv, long repeat) {
     for (j = 0; j < argc; j++)
         argvlen[j] = sdslen(argv[j]);
 
+    /* Negative repeat is allowed and causes infinite loop,
+       works well with the interval option. */
     while(repeat < 0 || repeat-- > 0) {
         redisAppendCommandArgv(context,argc,(const char**)argv,argvlen);
         while (config.monitor_mode) {