Ticket #30970: 30970.diff

src/wp-includes/query.php

@@ -4627 +4627 @@
          * @global int             $more
          * @global int             $numpages
          *
-         * @param WP_Post $post Post data.
+         * @param WP_Post|stdClass|int $post WP_Post instace or Post ID/object, which will be converted into WP_Post.
          * @return true True when finished.
          */
         public function setup_postdata( $post ) {
                 global $id, $authordata, $currentday, $currentmonth, $page, $pages, $multipage, $more, $numpages;
 
+                if ( ! ( $post instanceof WP_Post ) ) {
+                        $post = get_post( $post );
+                }
+
                 $id = (int) $post->ID;
 
                 $authordata = get_userdata($post->post_author);
@@ -4701 +4705 @@
         public function reset_postdata() {
                 if ( ! empty( $this->post ) ) {
                         $GLOBALS['post'] = $this->post;
-                        setup_postdata( $this->post );
+                        $this->setup_postdata( $this->post );
                 }
         }
 }
@@ -4772 +4776 @@
  *
  * @global WP_Query $wp_query
  *
- * @param object $post Post data.
+ * @param WP_Post|stdClass|int $post WP_Post instace or Post ID/object, which will be converted into WP_Post.
  * @return bool True when finished.
  */
 function setup_postdata( $post ) {

tests/phpunit/tests/query/setupPostdata.php

@@ -46 +46 @@
                 $this->assertSame( $p->ID, $GLOBALS['id'] );
         }
 
+        public function test_setup_by_id() {
+                $p = $this->factory->post->create_and_get();
+                setup_postdata( $p->ID );
+
+                $this->assertNotEmpty( $p->ID );
+                $this->assertSame( $p->ID, $GLOBALS['id'] );
+        }
+
+        public function test_fake_post() {
+
+                $fake = new stdClass;
+                $fake->ID = 100;
+
+                $this->assertNotSame( $fake->ID, $GLOBALS['id'] );
+        }
+
         public function test_authordata() {
                 $u = $this->factory->user->create_and_get();
                 $p = $this->factory->post->create_and_get( array(