Description

In the post editor, if you have an image block with an image that is smaller than the width of the post container and you specify an aspect ratio without selecting a width or height dimension, the image is incorrectly scaling up to fill the width of the container.

Step-by-step reproduction instructions

Screenshots use https://github.com/WordPress/wordpress-develop/blob/62b286f9b2ebc7bb609827a09fcf5136cac5fa01/tests/phpunit/data/images/a2-small.jpg for testing.

1. Use the following image block content or create a block includes an aspect ratio (and scale), but no width or height.

<!-- wp:image {"id":443,"aspectRatio":"3/4","scale":"cover","sizeSlug":"full","linkDestination":"none"} -->
<figure class="wp-block-image size-full"><img src="http://wp.local/wp-content/uploads/2023/06/a2-small.jpg" alt="" class="wp-image-443" style="aspect-ratio:3/4;object-fit:cover"/></figure>
<!-- /wp:image -->

3. See that the image fills the width of the editor instead of the width of the image.

Screenshots, screen recording, code snippet

Environment info

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes