Ticket #43760: 43760.1.diff

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 );
+        }
+
+
+        if ( ! class_exists( 'Text_Diff', false ) ) {
+                require( ABSPATH . WPINC . '/wp-diff.php' );
+        }
+
+        $left_lines  = explode( "\n", $post_data['post_content'] );
+        $right_lines = explode( "\n", $autosave_data['post_content'] );
+
+        $diff = new Text_Diff( $left_lines, $right_lines );
+
+        $total_lines   = count( $left_lines );
+        $edits         = array_map( 'get_class', $diff->getDiff() );
+        $changed_lines = count( $edits );
+        $counts        = array_count_values( $edits );
+        if ( ! empty( $counts['Text_Diff_Op_copy'] ) ) {
+                $changed_lines -= $counts['Text_Diff_Op_copy'];
+        }
+
+        /**
+         * Filter the change percentage threshold.
+         *
+         * @since 5.0.0
+         *
+         * @param int $percent_changed_threshold The threshold percentage.
+         * @param int $post_data                 The current post data.
+         */
+        $percent_changed_threshold = apply_filters( 'wp_create_revision_for_autosave_threshold', 25, $post_data );
+        
+        $percent_changed = ( $changed_lines / $total_lines ) * 100;
+        $create_revision = $percent_changed > $percent_changed_threshold;
+
+        /**
+         * 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 array $autosave_data   The calculated autosave difference.
+         */
+        if ( apply_filters( 'wp_create_revision_for_autosave', $create_revision, $post_data, $autosave_data ) ) {
+                _wp_put_post_revision( $post_data );
+        }
+}

tests/phpunit/tests/post/revisions.php

@@ -576 +576 @@
 
                 $this->assertEquals( $revision_ids, array_values( wp_list_pluck( $revisions, 'ID' ) ) );
         }
+
+        /**
+         * @ticket 43760
+         *
+         * @dataProvider get_test_wp_create_revision_for_autosave
+         */
+        public function test_wp_create_revision_for_autosave( $post_content, $autosave_data, $revision ) {
+                $post = self::factory()->post->create_and_get(
+                        array(
+                                'post_type'    => 'post',
+                                'post_content' => $post_content,
+                        )
+                );
+
+                $post_data = array(
+                        'post_content' => $autosave_data,
+                );
+
+                wp_create_revision_for_autosave( $post, $post_data );
+
+                $revisions = wp_get_post_revisions( $post->ID );
+                $this->assertTrue( ! ( count( $revisions ) xor $revision ) );
+        }
+
+        public function get_test_wp_create_revision_for_autosave() {
+                return array(
+                        array(
+                                "some content\nmore content",
+                                "some content\nwhat content",
+                                true,
+                        ),
+                        array(
+                                "some content\nmore content",
+                                "some content",
+                                true,
+                        ),
+                        array(
+                                "some content\nhello world\nwhere is\nthe diff",
+                                "some content\nhello world\nwhere is\nthe diffs",
+                                false,
+                        ),
+                );
+        }
 }