File block: Center alignment option does not center block's text in editor

[sabernhardt]

Description

Reported by pitamdey on Trac 58923, similar bug previously fixed in #8303

The File block Center alignment does not work in the editor with classic themes unless they have their own styles for centering blocks.

The front-end block styles include text-align: center, but editor.scss does not include a similar rule such as this:

.wp-block-file {
	.wp-block[data-align="center"] > & {
		text-align: center;
	}

Step-by-step reproduction instructions

1. Activate Twenty Seventeen (or any earlier default theme).
2. Add a new post.
3. Insert a File block with the text link and download button.
4. Choose the "Align center" option in the block toolbar.
5. Save the post, and view/preview how it appears on the front end.

Screenshots, screen recording, code snippet

iframe editor, with Twenty Seventeen in WordPress 6.5-RC2:

front end:

Environment info

• WordPress 6.5-RC2, without Gutenberg
• default themes from Twenty Ten to Twenty Seventeen, with and without iframe (Twenty Nineteen shows the same issue, but it also has its own bug with the download button)
• desktop with Windows 10
• Firefox 123.0.1

I also tested once with Gutenberg 17.9.0, using Twenty Seventeen and the iframe editor, to confirm it still happens with the plugin active.

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