Symfony version(s) affected:
symfony/console v4.4.13 Symfony Console Component

Description

Referring to this class, https://github.com/symfony/console/blob/master/Input/ArgvInput.php, I ran into a situation where $argv is NULL by default and in turn caused $this->tokens to be NULL. This will cause an exception to be thrown when foreach() is applied on $this->tokens below:

• https://github.com/symfony/console/blob/a729c1d1f122a0f3a356f0882400d63cb44c9d5c/Input/ArgvInput.php#L243
• https://github.com/symfony/console/blob/a729c1d1f122a0f3a356f0882400d63cb44c9d5c/Input/ArgvInput.php#L279

How to reproduce

Many have reported about it in the past decade:

• https://stackoverflow.com/questions/57848968/invalid-argument-supplied-for-foreach-in-laravel-schedular-job
• https://laracasts.com/discuss/channels/laravel/invalid-argument-supplied-for-foreach-when-scheduling-task
• https://stackoverflow.com/questions/49149556/laravel-5-5-cron-job-proc-open-and-argvinput-problems

Possible Solution

Never allow $this->tokens to be NULL, at minimum, it should be an empty array.

1. In __construct(), change the assign to call $this->setTokens($argv);
2. In setTokens(), if (null == $tokens) $tokens = [];

Additional context

In the cases above (including my own), this exception does not link back to the offending code and becomes a real challenge to trace. I can submit a PR. Thank you.