Formatting: Ensure `wpautop()` isn't run on content generated from blocks.

As `do_blocks()` is run before `wpautop()` in the_content filter, we can remove in a Just In Time fashion, before that filter is run.

After `wpautop()`s original priority has passed, we can re-add it in a Just Too Late fashion, to ensure it's available if `the_content` filter is run multiple times on a page load.

Merges [43879] and [43881] from the 5.0 branch to trunk.

Props pento, nerrad.
Fixes #45290.

Built from https://develop.svn.wordpress.org/trunk@44226


git-svn-id: http://core.svn.wordpress.org/trunk@44056 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/blocks.php

@@ -198,10 +198,38 @@ function parse_blocks( $content ) {
  * @return string Updated post content.
  */
 function do_blocks( $content ) {
+	// If there are blocks in this content, we shouldn't run wpautop() on it later.
+	$priority = has_filter( 'the_content', 'wpautop' );
+	if ( false !== $priority && doing_filter( 'the_content' ) && has_blocks( $content ) ) {
+		remove_filter( 'the_content', 'wpautop', $priority );
+		add_filter( 'the_content', '_restore_wpautop_hook', $priority + 1 );
+	}
+
 	$blocks = parse_blocks( $content );
 	return _recurse_do_blocks( $blocks, $blocks );
 }
 
+/**
+ * If do_blocks() needs to remove wp_autop() from the `the_content` filter, this re-adds it afterwards,
+ * for subsequent `the_content` usage.
+ *
+ * @access private
+ *
+ * @since 5.0.0
+ *
+ * @param string $content The post content running through this filter.
+ * @return string The unmodified content.
+ */
+function _restore_wpautop_hook( $content ) {
+	global $wp_filter;
+	$current_priority = $wp_filter['the_content']->current_priority();
+
+	add_filter( 'the_content', 'wpautop', $current_priority - 1 );
+	remove_filter( 'the_content', '_restore_wpautop_hook', $current_priority );
+
+	return $content;
+}
+
 /**
  * Helper function for do_blocks(), to recurse through the block tree.
  *

wp-includes/formatting.php

@@ -458,11 +458,6 @@ function wpautop( $pee, $br = true ) {
 		return '';
 	}
 
-	// We don't need to autop posts with blocks in them.
-	if ( has_blocks( $pee ) ) {
-		return $pee;
-	}
-
 	// Just to make things a little easier, pad the end.
 	$pee = $pee . "\n";
 

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.1-alpha-44225';
+$wp_version = '5.1-alpha-44226';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.