Make in_category() an alias of has_category(). fixes #16718.

Built from https://develop.svn.wordpress.org/trunk@25119


git-svn-id: http://core.svn.wordpress.org/trunk@25099 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/category-template.php

@@ -225,16 +225,14 @@ function get_the_category_list( $separator = '', $parents='', $post_id = false )
  * As of 2.7, the function can be used anywhere if it is provided a post ID or post object.
  *
  * @since 1.2.0
+ * @uses has_category()
  *
  * @param int|string|array $category Category ID, name or slug, or array of said.
  * @param int|object $post Optional. Post to check instead of the current post. (since 2.7.0)
  * @return bool True if the current post is in any of the given categories.
  */
 function in_category( $category, $post = null ) {
-	if ( empty( $category ) )
-		return false;
-
-	return has_term( $category, 'category', $post );
+	return has_category( $category, $post );
 }
 
 /**