Changeset 46974

Timestamp:

12/17/2019 08:41:09 PM (7 years ago)

Author:

SergeyBiryukov

Message:

Date/Time: Ensure that get_feed_build_date() correctly handles a modified post object with invalid date.

• Clarify in the documentation that the function returns false on failure.
• Consistently pass the return value through the get_feed_build_date filter.

Props Rarst, dd32, azaozz, tellyworth.
Fixes #48957.

Location:

trunk

Files:

• src/wp-includes/feed.php (modified) (3 diffs)
• tests/phpunit/tests/date/getFeedBuildDate.php (modified) (1 diff)

trunk/src/wp-includes/feed.php

@@ -649 +649 @@
 
 /**
- * Get the timestamp of the most recently modified post from WP_Query.
- *
- * If viewing a comment feed, the timestamp of the most recently modified
+ * Get the UTC time of the most recently modified post from WP_Query.
+ *
+ * If viewing a comment feed, the time of the most recently modified
  * comment will be returned.
  *
@@ -658 +658 @@
  * @since 5.2.0
  *
- * @param string $format Format of the timestamp to return, passed to mysql2date.
- *
- * @return string The timestamp.
+ * @param string $format Date format string to return the time in.
+ * @return string|false The time in requested format, or false on failure.
  */
 function get_feed_build_date( $format ) {
         global $wp_query;
 
-        if ( empty( $wp_query ) || ! $wp_query->have_posts() ) {
-                // Fallback to last time any post was modified or published.
-                return get_lastpostmodified( 'GMT' );
-        }
-
-        // Extract the post modified times from the posts.
-        $modified_times = wp_list_pluck( $wp_query->posts, 'post_modified_gmt' );
-
-        // If this is a comment feed, check those objects too.
-        if ( $wp_query->is_comment_feed() && $wp_query->comment_count ) {
-                // Extract the comment modified times from the comments.
-                $comment_times = wp_list_pluck( $wp_query->comments, 'comment_date_gmt' );
-
-                // Add the comment times to the post times for comparison.
-                $modified_times = array_merge( $modified_times, $comment_times );
-        }
-
-        // Determine the maximum modified time.
-        $datetime = date_create_immutable_from_format(
-                'Y-m-d H:i:s',
-                max( $modified_times ),
-                new DateTimeZone( 'UTC' )
-        );
-
-        $max_modified_time = $datetime->format( $format );
+        $datetime          = false;
+        $max_modified_time = false;
+        $utc               = new DateTimeZone( 'UTC' );
+
+        if ( ! empty( $wp_query ) && $wp_query->have_posts() ) {
+                // Extract the post modified times from the posts.
+                $modified_times = wp_list_pluck( $wp_query->posts, 'post_modified_gmt' );
+
+                // If this is a comment feed, check those objects too.
+                if ( $wp_query->is_comment_feed() && $wp_query->comment_count ) {
+                        // Extract the comment modified times from the comments.
+                        $comment_times = wp_list_pluck( $wp_query->comments, 'comment_date_gmt' );
+
+                        // Add the comment times to the post times for comparison.
+                        $modified_times = array_merge( $modified_times, $comment_times );
+                }
+
+                // Determine the maximum modified time.
+                $datetime = date_create_immutable_from_format( 'Y-m-d H:i:s', max( $modified_times ), $utc );
+        }
+
+        if ( false === $datetime ) {
+                // Fall back to last time any post was modified or published.
+                $datetime = date_create_immutable_from_format( 'Y-m-d H:i:s', get_lastpostmodified( 'GMT' ), $utc );
+        }
+
+        if ( false !== $datetime ) {
+                $max_modified_time = $datetime->format( $format );
+        }
 
         /**
@@ -696 +699 @@
          * @since 5.2.0
          *
-         * @param string $max_modified_time Date the last post or comment was modified in the query.
-         * @param string $format            The date format requested in get_feed_build_date.
+         * @param string|false $max_modified_time Date the last post or comment was modified in the query, in UTC.
+         *                                        False on failure.
+         * @param string       $format            The date format requested in get_feed_build_date().
          */
         return apply_filters( 'get_feed_build_date', $max_modified_time, $format );

trunk/tests/phpunit/tests/date/getFeedBuildDate.php

@@ -38 +38 @@
                 $this->assertEquals( '2018-07-23T03:13:23+00:00', get_feed_build_date( DATE_RFC3339 ) );
         }
+
+        /**
+         * Test that get_feed_build_date() works with invalid post dates.
+         *
+         * @ticket 48957
+         */
+        public function test_should_fall_back_to_last_post_modified() {
+                global $wp_query;
+
+                update_option( 'timezone_string', 'Europe/Kiev' );
+                $datetime     = new DateTimeImmutable( 'now', wp_timezone() );
+                $datetime_utc = $datetime->setTimezone( new DateTimeZone( 'UTC' ) );
+
+                $wp_query->posts = array();
+
+                $this->assertFalse( get_feed_build_date( DATE_RFC3339 ), 'False when unable to determine valid time' );
+
+                $this->factory->post->create(
+                        array(
+                                'post_date' => $datetime->format( 'Y-m-d H:i:s' ),
+                        )
+                );
+
+                $this->assertEquals(
+                        $datetime_utc->format( DATE_RFC3339 ),
+                        get_feed_build_date( DATE_RFC3339 ),
+                        'Fall back to time of last post modified with no posts'
+                );
+
+                $post_id_broken = $this->factory->post->create();
+                $post_broken    = get_post( $post_id_broken );
+
+                $post_broken->post_modified_gmt = 0;
+
+                $wp_query->posts = array( $post_broken );
+
+                $this->assertEquals(
+                        $datetime_utc->format( DATE_RFC3339 ),
+                        get_feed_build_date( DATE_RFC3339 ),
+                        'Fall back to time of last post modified with broken post object'
+                );
+        }
 }