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.

See #45113.



git-svn-id: https://develop.svn.wordpress.org/branches/5.0@43758 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-editor.php

@@ -81,7 +81,8 @@ final class _WP_Editors {
 		$settings = apply_filters( 'wp_editor_settings', $settings, $editor_id );
 
 		$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,