In HTML5, the action attribute is no longer required. Remove this attribute when empty.

The admin HTML is served with the HTML5 doctype.

"The action and formaction content attributes, if specified, must have a value that is a valid non-empty URL potentially surrounded by spaces." 
http://www.w3.org/html/wg/drafts/html/master/forms.html#attr-fs-action

Props voldemortensen.
Fixes #30126.


git-svn-id: https://develop.svn.wordpress.org/trunk@31200 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/theme-install.php

@@ -57,7 +57,7 @@ function install_theme_search_form( $type_selector = true ) {
 	if ( ! $type_selector )
 		echo '<p class="install-help">' . __( 'Search for themes by keyword.' ) . '</p>';
 	?>
-<form id="search-themes" method="get" action="">
+<form id="search-themes" method="get">
 	<input type="hidden" name="tab" value="search" />
 	<?php if ( $type_selector ) : ?>
 	<label class="screen-reader-text" for="typeselector"><?php _e('Type of search'); ?></label>
@@ -99,7 +99,7 @@ function install_themes_dashboard() {
 <h4><?php _e('Feature Filter') ?></h4>
 <p class="install-help"><?php _e( 'Find a theme based on specific features.' ); ?></p>
 
-<form method="get" action="">
+<form method="get">
 	<input type="hidden" name="tab" value="search" />
 	<?php
 	$feature_list = get_theme_feature_list();