Posts, Post Types: Check the result of creating a draft in get_default_post_to_edit().

As `wp_insert_post()` can return an error for various reasons, this commit ensures that this scenario is properly handled and an error message is displayed.

Follow-up to [12987].

Props rishabhwp, tfrommen, SirLouen, siliconforks, SergeyBiryukov.
Fixes #37441.

git-svn-id: https://develop.svn.wordpress.org/trunk@60701 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-admin/includes/post.php

@@ -768,13 +768,20 @@ function get_default_post_to_edit( $post_type = 'post', $create_in_db = false )
 				'post_type'   => $post_type,
 				'post_status' => 'auto-draft',
 			),
-			false,
+			true,
 			false
 		);
-		$post    = get_post( $post_id );
+
+		if ( is_wp_error( $post_id ) ) {
+			wp_die( $post_id->get_error_message() );
+		}
+
+		$post = get_post( $post_id );
+
 		if ( current_theme_supports( 'post-formats' ) && post_type_supports( $post->post_type, 'post-formats' ) && get_option( 'default_post_format' ) ) {
 			set_post_format( $post, get_option( 'default_post_format' ) );
 		}
+
 		wp_after_insert_post( $post, false, null );
 
 		// Schedule auto-draft cleanup.

tests/phpunit/tests/admin/includesPost.php

@@ -534,6 +534,20 @@ public function test_bulk_edit_posts_should_fire_bulk_edit_posts_action() {
 		$this->assertSame( 1, $action->get_call_count() );
 	}
 
+	/**
+	 * Tests that get_default_post_to_edit() calls wp_die() if wp_insert_post() returns a WP_Error.
+	 *
+	 * @ticket 37441
+	 *
+	 * @covers ::get_default_post_to_edit
+	 */
+	public function test_get_default_post_to_edit_with_wp_insert_post_error() {
+		add_filter( 'wp_insert_post_empty_content', '__return_true' );
+
+		$this->expectException( 'WPDieException' );
+		get_default_post_to_edit( 'post', true );
+	}
+
 	/**
 	 * @ticket 38293
 	 */