From 3756e141a1c66ab52d272fc4688803b4897954de Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Tue, 11 Sep 2012 10:32:04 +0200
Subject: [PATCH] Make sure that SELECT argument is an integer or return an
 error.

Unfortunately we had still the lame atoi() without any error checking in
place, so "SELECT foo" would work as "SELECT 0". This was not an huge
problem per se but some people expected that DB can be strings and not
just numbers, and without errors you get the feeling that they can be
numbers, but not the behavior.

Now getLongFromObjectOrReply() is used as almost everybody else across
the code, generating an error if the number is not an integer or
overflows the long type.

Thanks to @mipearson for reporting that on Twitter.
---
 src/db.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/db.c b/src/db.c
index ecbeaacbcc8b..2e034c5ae968 100644
--- a/src/db.c
+++ b/src/db.c
@@ -244,7 +244,11 @@ void existsCommand(redisClient *c) {
 }
 
 void selectCommand(redisClient *c) {
-    int id = atoi(c->argv[1]->ptr);
+    long id;
+
+    if (getLongFromObjectOrReply(c, c->argv[1], &id,
+        "invalid DB index") != REDIS_OK)
+        return;
 
     if (selectDb(c,id) == REDIS_ERR) {
         addReplyError(c,"invalid DB index");