Ticket #43760: 43760.patch

src/wp-admin/includes/post.php

@@ -1780 +1780 @@
                         return 0;
                 }
 
+                // Add a revision if the content is significantly different.
+                wp_create_revision_for_autosave( $old_autosave, $new_autosave );
+
                 /**
                  * Fires before an autosave is stored.
                  *
@@ -1894 +1897 @@
         }
 
         if ( ! wp_check_post_lock( $post->ID ) && get_current_user_id() == $post->post_author && ( 'auto-draft' == $post->post_status || 'draft' == $post->post_status ) ) {
+                // Add a revision if the content is significantly different.
+                wp_create_revision_for_autosave( $post, wp_slash( $post_data ) );
+
                 // Drafts and auto-drafts are just overwritten by autosave for the same user if the post is not locked
                 return edit_post( wp_slash( $post_data ) );
         } else {

src/wp-includes/revision.php

@@ -768 +768 @@
 
         return true;
 }
+
+/**
+ * Create a revision when the autosave content is significantly different.
+ *
+ * If the autosave content is significantly different from the current post or the previous autosave,
+ * create a revision from the old data.
+ *
+ * @since 5.0.0
+ *
+ * @param WP_Post $post          The current post or the previous autosave revision.
+ * @param array   $autosave_data The autosave data.
+ */
+function wp_create_revision_for_autosave( $post, $autosave_data ) {
+
+        if ( ! wp_revisions_enabled( $post ) ) {
+                return;
+        }
+
+        $post_data = get_object_vars( $post );
+
+        if ( $post_data['post_type'] === 'revision' ) {
+                // If the old post is a revision, need to merge it with the actual post.
+                $parent_post = $this->get_parent( $post_data['post_parent'] );
+                foreach ( array_keys( _wp_post_revision_fields( $parent_post ) ) as $field ) {
+                        if ( isset( $post_data[ $field ] ) ) {
+                                $parent_post->$field = $post_data[ $field ];
+                        }
+                }
+                $post_data = get_object_vars( $parent_post );
+        }
+
+        $old_length = strlen( $post_data['post_content'] );
+
+        if ( $old_length > 1000 ) {
+                $difference = 250;
+        } elseif ( $old_length > 500 ) {
+                $difference = (int) $old_length * 0.2;
+        } elseif ( $old_length > 50 ) {
+                $difference = (int) $old_length * 0.3;
+        } else {
+                $difference = (int) $old_length * 0.5;
+        }
+
+        $size_diff = strlen( $autosave_data['post_content'] ) - $old_length;
+        $create_revision = absint( $size_diff ) > $difference;
+
+        /**
+         * Filter whether a revision is created when an autosave is made via the REST API.
+         *
+         * @since 5.0.0
+         *
+         * @param bool  $create_revision Create a revision?
+         * @param array $post_data       The current post data.
+         * @param int   $size_diff       The calculated autosave difference.
+         */
+        if ( apply_filters( 'wp_create_revision_for_autosave', $create_revision, $post_data, $size_diff ) ) {
+                _wp_put_post_revision( $post_data );
+        }
+}