Block Editor: $editor_styles bug.

[gqevu6bsiz]

WP 5.0.2 with TwentySeventeen, it is PHP Warning error on Post Edit/Add New Post screen.

PHP Warning: file_get_contents(/wp-content/themes/twentyseventeen): failed to open stream: Permission denied in wp-admin/edit-form-blocks.php on line 200

It seems to editor_style file is nothing. This problem looks like TwentySeventeen, but I think it would be better to empty check for all themes.

And TwentyNinteen, activate to Classic Editor is not get same problem.

Example To

	foreach ( $editor_styles as $style ) {
>>                if ( empty( $style ) ) {
>>                    continue;
>>                }
		if ( preg_match( '~^(https?:)?//~', $style ) ) {
			$response = wp_remote_get( $style );
			if ( ! is_wp_error( $response ) ) {
				$styles[] = array(
					'css' => wp_remote_retrieve_body( $response ),
				);
			}
		} else {
			$file = get_theme_file_path( $style );
			if ( file_exists( $file ) ) {
				$styles[] = array(
					'css'     => file_get_contents( $file ),
					'baseURL' => get_theme_file_uri( $style ),
				);
			}
		}
        }

[pento]

In 45619:

Block Editor: Avoid a PHP warning when a theme adds an editor style with an empty filename.

Fixes #45739.

[JeffPaul]

Reopening this so it can be back-ported to the 5.2 branch, also needs testing to validate if this ticket is good to land in 5.2.3.

[SergeyBiryukov]

In 45829:

Block Editor: Avoid a PHP warning when a theme adds an editor style with an empty filename.

Props pento, gqevu6bsiz.
Merges [45619] to the 5.2 branch.
Fixes #45739.

[sabernhardt]

#45880 was marked as a duplicate.