From a92ae7774052ebdb305249ac548d5ed4f7887b82 Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Fri, 27 Jun 2014 12:05:54 +0200
Subject: [PATCH] COMMAND: fix argument parsing.

This fixes detection of wrong subcommand (that resulted in the default
all-commands output instead) and allows COMMAND INFO to be called
without arguments (resulting into an empty array) which is useful in
programmtically generated calls like the following (in Ruby):

    redis.commands("command","info",*mycommands)

Note: mycommands may be empty.
---
 src/redis.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/redis.c b/src/redis.c
index 33369294..393b4225 100644
--- a/src/redis.c
+++ b/src/redis.c
@@ -2403,6 +2403,7 @@ void timeCommand(redisClient *c) {
 }
 
 
+/* Helper function for addReplyCommand() to output flags. */
 int addReplyCommandFlag(redisClient *c, struct redisCommand *cmd, int f, char *reply) {
     if (cmd->flags & f) {
         addReplyStatus(c, reply);
@@ -2411,6 +2412,7 @@ int addReplyCommandFlag(redisClient *c, struct redisCommand *cmd, int f, char *r
     return 0;
 }
 
+/* Output the representation of a Redis command. Used by the COMMAND command. */
 void addReplyCommand(redisClient *c, struct redisCommand *cmd) {
     if (!cmd) {
         addReply(c, shared.nullbulk);
@@ -2446,26 +2448,27 @@ void addReplyCommand(redisClient *c, struct redisCommand *cmd) {
     }
 }
 
+/* COMMAND <subcommand> <args> */
 void commandCommand(redisClient *c) {
     dictIterator *di;
     dictEntry *de;
 
-    if (c->argc > 2 && !strcasecmp(c->argv[1]->ptr, "info")) {
-        int i;
-        addReplyMultiBulkLen(c, c->argc-2);
-        for (i = 2; i < c->argc; i++) {
-            addReplyCommand(c, dictFetchValue(server.commands, c->argv[i]->ptr));
-        }
-    } else if (c->argc > 2) {
-        addReplyError(c, "Unknown subcommand.");
-        return;
-    } else {
+    if (c->argc == 1) {
         addReplyMultiBulkLen(c, dictSize(server.commands));
         di = dictGetIterator(server.commands);
         while ((de = dictNext(di)) != NULL) {
             addReplyCommand(c, dictGetVal(de));
         }
         dictReleaseIterator(di);
+    } else if (!strcasecmp(c->argv[1]->ptr, "info")) {
+        int i;
+        addReplyMultiBulkLen(c, c->argc-2);
+        for (i = 2; i < c->argc; i++) {
+            addReplyCommand(c, dictFetchValue(server.commands, c->argv[i]->ptr));
+        }
+    } else {
+        addReplyError(c, "Unknown subcommand.");
+        return;
     }
 }