I was testing CakePHP framework with PHP 7 and some tests were failing. Digging into the issue I found that using compact in a certain way can cause PHP to create an array with length but no content inside.
I reported and added some examples on how to reproduce on https://bugs.php.net/bug.php?id=69198 I'm sending this email more to bring the attention that this can be a potential issue on the engine since other places can have the same issue or even non-internals extensions can generate this kind of weirdness. I wonder if doing this can cause some security issue. Thanks, Juan Basso
