ithackston

Selecting “Full Size” passes in the dimensions of the full size image to image_resize_dimensions(), which returns false since we don’t need to resize the image. When image_resize_dimensions() returns false, image_resize() returns an error object.
http://core.trac.wordpress.org/ticket/12268

So the following if statement does not do what it should:
if ($image = image_resize( $imgpath, $width, $height ))

To make it work, we test if the original dimensions are the same as the destination dimensions before passing them in to image_resize().

Change lines 76-80 of image-widget.php from:

if ($image = image_resize( $imgpath, $width, $height )) {
	$image = path_join( dirname($attachment_url), basename($image) );
} else {
	$image = $attachment_url;
}

To:

//Get original image size
$size = @getimagesize( $imgpath );
list($orig_w, $orig_h, $orig_type) = $size;
$image = image_resize( $imgpath, $width, $height );

if ( ($orig_w == $width && $orig_h == $height) || !$image) {
	$image = $attachment_url; //No resizing necessary.
} else {
	$image = path_join( dirname($attachment_url), basename($image) );
}

You will need to hit “Save” on each active widget to make the image appear.