Enable additional safeguards against read-only filesystems

[cezarpopa-cognita]

Hi,

first i wanted to say thank you for this great plugin, as this is my first commit to the repository i hope it accepts pull requests.
I am using the plugin with WordPress VIP and due to the nature of the hosting setup i do not have write permissions on some folders.

Due to that, each time i visit a page the plugin will try to write to the read-only fs trigger dozens of notices for each request.

I have tested this and so far i can't see anything obvious that i have missed from the core functionality, having those checks in place so far seems to keep the functionality as is and keeps my logs a lot cleaner.

Thank you,
Cezar

[kprovance]

Looks good. I don't see any issues and will give it a spin. That said, we still have about 30+ million users. It's the scenarios I can't predict that always get me. In the event there are widespread issues (because WP's filesystem API sucks), I'll have to roll it back and we can revisit the cause. I don't see that happening, but I've said that before and been bitten by it. ;-)

[cezarpopa-cognita]

Looks good. I don't see any issues and will give it a spin. That said, we still have about 30+ million users. It's the scenarios I can't predict that always get me. In the event there are widespread issues (because WP's filesystem API sucks), I'll have to roll it back and we can revisit the cause. I don't see that happening, but I've said that before and been bitten by it. ;-)

Thanks for that, i understand and wasn't aware the number of active users was that big.
On that note i am not sure if GitHub is just acting up. I have received a notification about a timeout in the class-redux-wp-filesystem.php which i can't see on the PR. Does the timeout still apply?

With regards to the scenarios, i will try to invest some time researching if we can get some form of tests in place maybe? Thanks again!