Twenty Seventeen: Add filter for display of featured image in header.

When a layout doesn't use custom post types it was appearing broken. This adds a filter for the display of the featured image to resolve this.

Props justnorris, JPry, davidakennedy, SergeyBiryukov, zkarj, poena, nhrrob, lamarajan.
Fixes #39281.

Built from https://develop.svn.wordpress.org/trunk@58206


git-svn-id: http://core.svn.wordpress.org/trunk@57669 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-content/themes/twentyseventeen/functions.php

@@ -689,6 +689,19 @@ if ( ! function_exists( 'wp_get_list_item_separator' ) ) :
 	}
 endif;
 
+/**
+ * If a regular post or page, and not the front page, show the featured image below the header.
+ * Using get_queried_object_id() here since the $post global may not be set before a call to the_post().
+ *
+ * @since Twenty Seventeen 3.7
+ *
+ * @return bool Whether the post thumbnail should be shown.
+ */
+function twentyseventeen_should_show_featured_image() {
+	$show_featured_image = ( is_single() || ( is_page() && ! twentyseventeen_is_frontpage() ) ) && has_post_thumbnail( get_queried_object_id() );
+	return apply_filters( 'twentyseventeen_should_show_featured_image', $show_featured_image );
+}
+
 /**
  * Implement the Custom Header feature.
  */

wp-content/themes/twentyseventeen/header.php

@@ -47,12 +47,7 @@
 	</header><!-- #masthead -->
 
 	<?php
-
+	if ( twentyseventeen_should_show_featured_image() ) :
-	/*
-	 * If a regular post or page, and not the front page, show the featured image.
-	 * Using get_queried_object_id() here since the $post global may not be set before a call to the_post().
-	 */
-	if ( ( is_single() || ( is_page() && ! twentyseventeen_is_frontpage() ) ) && has_post_thumbnail( get_queried_object_id() ) ) :
 		echo '<div class="single-featured-image-header">';
 		echo get_the_post_thumbnail( get_queried_object_id(), 'twentyseventeen-featured-image' );
 		echo '</div><!-- .single-featured-image-header -->';

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.6-alpha-58205';
+$wp_version = '6.6-alpha-58206';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.