Ticket #26979: 26979.2.diff

src/wp-includes/revision.php

@@ -33 +33 @@
                         'post_excerpt' => __( 'Excerpt' ),
                 );
 
-                // Runs only once
+                /**
+                 * Filter the list of fields saved in post revisions.
+                 *
+                 * Included by default: 'post_title', 'post_content' and 'post_excerpt'.
+                 *
+                 * Dissalowed: 'ID', 'post_name', 'post_parent', 'post_date', 'post_date_gmt', 'post_status', 'post_type',
+                 *     'comment_count' and 'post_author'.
+                 *
+                 * @since 2.5.1
+                 *
+                 * @param array $fields List of fields to revision. Contains 'post_title', 'post_content',
+                 *                      and 'post_excerpt' by default.
+                 *
+                 */
                 $fields = apply_filters( '_wp_post_revision_fields', $fields );
 
                 // WP uses these internally either in versioning or elsewhere - they cannot be versioned
@@ -99 +112 @@
                         }
                 }
 
-                if ( isset( $last_revision ) && apply_filters( 'wp_save_post_revision_check_for_changes', true, $last_revision, $post ) ) {
+                /**
+                 * Override check for chages in revisioned fields before saving a new revision.
+                 *
+                 * By default a revision is saved only if one of the revisioned fields has changed.
+                 * This filter can override that so a revision is saved even if nothing has changed.
+                 *
+                 * @since 3.6.0
+                 *
+                 * @param boolean $check_for_changes Check for changes before saving revision? Default true.
+                 *                                   Return false to bypass and save a new revision regardless.
+                 * @param int     $last_revision     The ID of the last revision.
+                 * @param int     $post              The ID of the post being saved as a revision.
+                 *
+                 */
+                if ( isset( $last_revision ) && apply_filters( 'wp_save_post_revision_check_for_changes', $check_for_changes = true, $last_revision, $post ) ) {
                         $post_has_changed = false;
 
                         foreach ( array_keys( _wp_post_revision_fields() ) as $field ) {
@@ -422 +449 @@
         if ( ! post_type_supports( $post->post_type, 'revisions' ) )
                 $num = 0;
 
+        /**
+         * Filter the number of revisions to save.
+         *
+         * Allows setting the number of revisions to save, overriding the default behaviour of saving
+         * an unlimited number of revsions. Overrides WP_POST_REVISIONS setting from wp-config.php (if any).
+         *
+         * @since 3.6.0
+         *
+         * @param int    $num  The number of revisions the store, overrides WP_POST_REVISIONS value.
+         *                     Older revisions are discarded when a new revision is added.
+         * @param object $post The post object.
+         *
+         */
         return (int) apply_filters( 'wp_revisions_to_keep', $num, $post );
 }