Incongruent returned value for wp_get_attachment_image_src

[wido]

As per docblock the function wp_get_attachment_image_src will return false|array Returns an array (url, width, height, is_intermediate), or false, if no image is available.

Function wp_get_attachment_image_src return an indexed array containing source, width and height, but not the intermediated value in case the internal call to image_downsize return false.

It's this latter that will return the array containing all of the elements, therefore if it's false wp_get_attachment_image_src will try to create them but will miss is_intermediated value.