Changeset 46974

Timestamp:

12/17/2019 08:41:09 PM (5 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'
+        );
+    }
 }