get_the_title() will pass an empty title and invalid post ID to 'the_title' filter on invalid post ID

[kawauso]

get_the_title() has a workaround for when an invalid post ID is passed, setting the title to an empty string and post ID to the requested ID, then passing this to 'the_title' filter.

Example:

function testme() {
	var_dump( get_the_title( 99999 ) );
}

function filterme( $title ) {
	return "[$title]";
}

add_action( 'wp_head', 'testme' );
add_filter( 'the_title', 'filterme' );

Is there a reason for this odd functionality?

[scribu]

I think it should just return false instead.

[solarissmoke]

This was done in #11435:

Fix notices in get_the_title() when passed an invalid id. Also ensure that the filter gets the invalid id so a plugin can supply a default title instead.

I fail to see why you would want a default title for a post that doesn't exist...

[c3mdigital]

Couldn't this be handled by doing a check if ( '0' == $post_id ) in your get_the_title filter? And I also fail to see why you would want a default title for a post that doesn't exist.