Warning about `$HTTP_RAW_POST_DATA` being deprecated

Been awhile until I came across this error. Put up my answer for anyone who may stumble upon this issue.

The error only means that you are sending an empty POST request. This error is commonly found on HTTPRequests with no parameters passed. To avoid this error, you can always add a parameter to the POST without changing the php.ini.

Like:

$.post(URL_HERE
    ,{addedvar : 'anycontent'}
    ,function(d){
       doAnyHere(d);
    }
    ,'json' //or 'html','text'
);

It turns out that my understanding of the error message was wrong. I'd say it features very poor choice of words. Googling around shown me someone else misunderstood the message exactly like I did - see PHP bug #66763.

After totally unhelpful "This is the way the RMs wanted it to be." response to that bug by Mike, Tyrael explains that setting it to "-1" doesn't make just the warning to go away. It does the right thing, i.e. it completely disables populating the culprit variable. Turns out that having it set to 0 STILL populates data under some circumstances. Talk about bad design! To cite PHP RFC:

Change always_populate_raw_post_data INI setting to accept three values instead of two.

• -1: The behavior of master; don't ever populate $GLOBALS[HTTP_RAW_POST_DATA]
• 0/off/whatever: BC behavior (populate if content-type is not registered or request method is other than POST)
• 1/on/yes/true: BC behavior (always populate $GLOBALS[HTTP_RAW_POST_DATA])

So yeah, setting it to -1 not only avoids the warning, like the message said, but it also finally disables populating this variable, which is what I wanted.