Enable Intermediate choice in UI if Full Size Image is exact match to Intermediate Image

[andrewteg]

This is simply a minor usability enhancement for Media Gallery. If an image is uploaded that is exactly the same size as an intermediate image (300x300 = Medium for example) it is not a choice when inserting that image into a post. It would be nice if it was a choice pointing to the full/original image since full is the same size as the intermediate.

It seems to be caused in the image_downsize function in /wp-includes/media.php because image_get_intermediate_size returns false.

I believe image_downsize can be updated as such to provide this enhancement:

Line 162 (if statement) Currently:

	if ( !$width && !$height && isset($meta['width'], $meta['height']) ) {
		// any other type: use the real image
		$width = $meta['width'];
		$height = $meta['height'];
	}

could be updated to read the intermediate width and height and set intermediate to true if it is an exact match to the original image:

	if ( !$width && !$height && isset($meta['width'], $meta['height']) ) {
		// any other type: use the real image
		$width = $meta['width'];
		$height = $meta['height'];
		// add check for real image being exact match to intermediate image to enable intermediate choice in UI
		if (isset($_wp_additional_image_sizes[$size])) {
			$goal_width = intval($_wp_additional_image_sizes[$size]['width']);
			$goal_height = intval($_wp_additional_image_sizes[$size]['height']);
		} else {
			$goal_width = get_option($size.'_size_w');
			$goal_height = get_option($size.'_size_h');
		}		
		if ($width == $goal_width && $height == $goal_height)
			$is_intermediate = true;
	}

Thanks for considering, and hope I put this in the right place,
Andrew