Feature Request (Or Bug Report?): Spoiler Tag on Images Should Also Apply to Comment

When posting an image to a text channel I have the ability to add a comment and mark the image as a spoiler. My expectation is that if I upload an image, flag it a spoiler, and add a comment that comment will also have a spoiler tag applied to it. This is currently not the case.

The spoiler checkbox is on the whole post, so it should apply to the whole post, not only the image.