[PHP7 Branch] Expire 0 no longer means "no expiration"

[steffenweber]

<?php
$redis = new Redis();
$redis->connect('localhost');
$redis->set('key', 'value', 0);

Using PHP 5.6.17 and phpredis 2.2.7 this yields "SET" "key" "value". Fine.

But using PHP 7.0.2 and the current HEAD of the php7 branch the same code sends nothing to the Redis server (observed using redis-cli with the MONITOR command). I guess this is a bug because IMHO the old behaviour (0 meaning "no expiration") is more intuitive.

[zzjin]

@steffenweber Same error here. But find reason at 01b46d0 .
But the latest release version was too old, and not included this fix.

[seyfer]

I had encountered this issue with phpredis 2.2.8 and php 5.6.24
and I have spent about one working day to guess why redis stopped to save value.

It was because I had ttl = 0 by default in my code ...
and it's worked on 2.2.7 before update to 2.2.8

[yatsukhnenko]

Probably fixed

[steffenweber]

I've tested again using PHP 7.1.7 and PhpRedis 3.1.3RC2: the bug is still there.

[michael-grunder]

Hey guys,

I'm not totally sure what the best thing to do is here. It is correct that the functionality changed from 2.2.7 -> 2.2.8, but the change is actually more correct from a Redis standpoint. Using a zero second expire is an error, and Redis will report it as such:

127.0.0.1:6379> setex foo 0 bar
(error) ERR invalid expire time in setex

Additionally, the 2.2.7 functionality is potentially more dangerous as it will silently write a never expiring key if sent a zero timeout. I believe this issue was raised by a different bug report while 2.2.8 was in progress.

I don't think changing the functionality back to what it was in 2.2.7 is really an option, as it's certain to break lots of people's code.

@yatsukhnenko Perhaps we could issue a warning to the user if sent an invalid expire argument?

[steffenweber]

Thank you for the feedback. I did not know that Redis reports an error for expire = 0.

That being said, the PhpRedis 2.2.7 behaviour still makes more sense to me from a PHP API perspective (for example, it mirrors the expire parameter of the setcookie function where 0 means "never expires").

On the other hand, I personally have adjusted my code and therefore have no problem at all with keeping the PhpRedis 2.2.8+ behaviour.

[yatsukhnenko]

@michael-grunder set command returns false which means failure. This is enough to understand that 0 is not valid expire value.