support POST/multipart Guzzle requests

[cirpo]

No description provided.

[Avariya]

Start to fix this problem, but can't reproduce it anymore. May you test is it still reproducible?

[cirpo]

@Avariya will do

[Avariya]

Ok. I found out that it fails at big files through multipart because of PHP max command length is 8192 at Win and 4096 at Linux.
https://github.com/php/php-src/blob/master/ext/standard/exec.c#L57
So escapeshellarg first of all checks is command it needs to escape longer than max one.
Need add trimming.
As an idea - trim to 4000 symbols or trim platformbase

Or use self written function like:

$input = str_replace('\'', '\\\'', $input);
return '\''.$input.'\'';

What kind of pull request should I create?