here’s the wp_get_attachment_image_scr function:
function wp_get_attachment_image_src($attachment_id, $size='thumbnail', $icon = false) {
// get a thumbnail or intermediate image if there is one
if ( $image = image_downsize($attachment_id, $size) )
return $image;
$src = false;
if ( $icon && $src = wp_mime_type_icon($attachment_id) ) {
/** This filter is documented in wp-includes/post.php */
$icon_dir = apply_filters( 'icon_dir', ABSPATH . WPINC . '/images/media' );
$src_file = $icon_dir . '/' . wp_basename($src);
@list($width, $height) = getimagesize($src_file);
}
if ( $src && $width && $height )
return array( $src, $width, $height );
return false;
} as u can see if 3-rd param is true then it looks in icons dir for that image ( and i assume wp_mime_type_icon returns default.png and some of your plugins add_filter to icon_dir to be wp-includes/images/crystal
Just remove 3-rd parameter in your example: $thumb_url_array = wp_get_attachment_image_src($thumb_id,'full'); and it should return false if no image or image url
