I have an <input type=file> with a local file selected, which I would like to upload to the server as a File, not as a Blob. I'm grabbing it with jQuery (element and then .files[0] or .prop('files')[0]).

By every indication but one, the prototype of this object is File:

Object.getPrototypeOf(file) // => File {slice: function}

file.__proto__              // => File {slice: function}

file.constructor            // => function File() { [native code] }

file.constructor.prototype  // => File {slice: function}

And yet:

file instanceof File        // => false

file instanceof Blob        // => true

What gives?