Two small fixes to maxclients handling.

1) Don't accept maxclients set to < 0
2) Allow maxclients < 1024, it is useful for testing.

src/config.c

@@ -155,6 +155,9 @@ void loadServerConfigFromString(char *config) {
             loadServerConfig(argv[1],NULL);
         } else if (!strcasecmp(argv[0],"maxclients") && argc == 2) {
             server.maxclients = atoi(argv[1]);
+            if (server.maxclients < 1) {
+                err = "Invalid max clients limit"; goto loaderr;
+            }
         } else if (!strcasecmp(argv[0],"maxmemory") && argc == 2) {
             server.maxmemory = memtoll(argv[1],NULL);
         } else if (!strcasecmp(argv[0],"maxmemory-policy") && argc == 2) {

src/redis.c

@@ -1135,7 +1135,6 @@ void adjustOpenFilesLimit(void) {
     rlim_t maxfiles = server.maxclients+32;
     struct rlimit limit;
 
-    if (maxfiles < 1024) maxfiles = 1024;
     if (getrlimit(RLIMIT_NOFILE,&limit) == -1) {
         redisLog(REDIS_WARNING,"Unable to obtain the current NOFILE limit (%s), assuming 1024 and setting the max clients configuration accordingly.",
             strerror(errno));