在php7.1版本时readSession 当redis返回null时 不是字符串报错

[hkui]

| Yii vesion 2.0.15
| PHP version 7.1
| Operating system centos
redis:4.0.2
`/**
* Session read handler.
* Do not call this method directly.
* @param string $id session ID
* @return string the session data
*/
public function readSession($id)
{
$data = $this->redis->executeCommand('GET', [$this->calculateKey($id)]);

    return $data === false ? '' : $data;
}`

$data=null时 就不全等于false了，返回的是null
session_start(): Failed to read session data: user (path: )
php7.1里readSession必须返回字符串

[cebe]

can you show a stack trace of the exception?

[hkui]

can you show a stack trace of the exception?

[machour]

Confirmed, I see this problem on the Cache component too, where getValue() returns NULL instead of false when checking for a key existence.

Redis returns "-1" when a key is not found, and this fall into this case:

yii2-redis/src/Connection.php

Lines 740 to 743 in 98fc1c5

	case '$': // Bulk replies
	if ($line == '-1') {
	return null;
	}