Classic Editor: Disable the wpautop TinyMCE plugin on block posts.

As the block editor adds its own `<p>` tags, disabling the wpautop stops the classic editor from removing them.

Props pento.

Merges [43758] to trunk.

See #45113.
Built from https://develop.svn.wordpress.org/trunk@44120


git-svn-id: http://core.svn.wordpress.org/trunk@43950 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-editor.php

@@ -82,7 +82,8 @@ final class _WP_Editors {
 		$set = wp_parse_args(
 			$settings,
 			array(
-				'wpautop'             => true,
+				// Disable autop if the current post has blocks in it.
+				'wpautop'             => ! has_blocks(),
 				'media_buttons'       => true,
 				'default_editor'      => '',
 				'drag_drop_upload'    => false,