Formatting: Add an extra line break before block elements in `wpautop()`.

`wpautop()` considers double line breaks to be the separator between block level HTML elements. By adding two line breaks before a block element, this allows us to process the text before a block element correctly.

Fixes #4857.


Built from https://develop.svn.wordpress.org/trunk@38592


git-svn-id: http://core.svn.wordpress.org/trunk@38535 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/formatting.php

@@ -469,7 +469,7 @@ function wpautop( $pee, $br = true ) {
 	$allblocks = '(?:table|thead|tfoot|caption|col|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|form|map|area|blockquote|address|math|style|p|h[1-6]|hr|fieldset|legend|section|article|aside|hgroup|header|footer|nav|figure|figcaption|details|menu|summary)';
 
 	// Add a single line break above block-level opening tags.
-	$pee = preg_replace('!(<' . $allblocks . '[\s/>])!', "\n$1", $pee);
+	$pee = preg_replace('!(<' . $allblocks . '[\s/>])!', "\n\n$1", $pee);
 
 	// Add a double line break below block-level closing tags.
 	$pee = preg_replace('!(</' . $allblocks . '>)!', "$1\n\n", $pee);

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-alpha-38591';
+$wp_version = '4.7-alpha-38592';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.