Wordpress theme Error "Fatal error: Cannot re-assign auto-global variable _POST"

Question

there's a error in this theme, http://www.mafiashare.net/download/sound-rock-music-band-wordpress-theme/ when I try to activate it, this show up

( ! ) SCREAM: Error suppression ignored for
( ! ) Fatal error: Cannot re-assign auto-global variable _POST in C:\wamp\www\web\wp-content\themes\soundrock\functions.php on line 48
Call Stack
#   Time    Memory  Function    Location
1   0.0014  364560  {main}( )   ..\themes.php:0
2   0.0043  433520  require_once( 'C:\wamp\www\web\wp-admin\admin.php' )    ..\themes.php:10
3   0.0048  451648  require_once( 'C:\wamp\www\web\wp-load.php' )   ..\admin.php:30
4   0.0052  463256  require_once( 'C:\wamp\www\web\wp-config.php' ) ..\wp-load.php:29
5   0.0061  553312  require_once( 'C:\wamp\www\web\wp-settings.php' )   ..\wp-config.php:90

so in functions.php on line 48, I removed this code, then the theme is working, but I want to why it's throwing an error?

function events_meta_save($_POST, $post_id) {
    global $wpdb;
    if ( empty($_POST["event_social_sharing"]) ) $_POST["event_social_sharing"] = "";
    if ( empty($_POST["event_start_time"]) ) $_POST["event_start_time"] = "";
    if ( empty($_POST["event_end_time"]) ) $_POST["event_end_time"] = "";
    if ( empty($_POST["event_all_day"]) ) $_POST["event_all_day"] = "";
    if ( empty($_POST["event_booking_url"]) ) $_POST["event_booking_url"] = "";
    if ( empty($_POST["event_address"]) ) $_POST["event_address"] = "";
        $sxe = new SimpleXMLElement("<event></event>");
            $sxe->addChild('event_social_sharing', $_POST["event_social_sharing"] );
            $sxe->addChild('event_start_time', $_POST["event_start_time"] );
            $sxe->addChild('event_end_time', $_POST["event_end_time"] );
            $sxe->addChild('event_all_day', $_POST["event_all_day"] );
            $sxe->addChild('event_booking_url', $_POST["event_booking_url"] );
            $sxe->addChild('event_address', $_POST["event_address"] );
                $sxe = save_layout_xml($sxe);
        update_post_meta( $post_id, 'cs_event_meta', $sxe->asXML() );
}

Solution

Replace

function events_meta_save($_POST, $post_id) {
    global $wpdb;
    if ( empty($_POST["event_social_sharing"]) ) $_POST["event_social_sharing"] = "";
    ....
    ....

with

function events_meta_save($_my_post, $post_id) {
    global $wpdb;
    if ( empty($_my_post["event_social_sharing"]) ) $_POST["event_social_sharing"] = "";
    ....
    ....

Do not forget to replace ALL $_POST inside the condition with $_my_post or any other name u like

Reason, as written in other answers:

You cannot use $_POST as a function / method argument

. Doing so attempts to re-assign the variable in the symbol table. Regard this as a saved keyword of the language. Putting it in a function signature is like defining new variable using a keyword of the language as the variable name.