Fix: wp menu item update --position does not reshuffle other menu items

features/menu-item.feature

@@ -195,6 +195,52 @@ Feature: Manage WordPress menu items
       | custom | First  | 1        | https://first.com  |
       | custom | Third  | 2        | https://third.com  |
 
+  Scenario: Menu order is recalculated on update
+    When I run `wp menu create "Sidebar Menu"`
+    Then STDOUT should not be empty
+
+    When I run `wp menu item add-custom sidebar-menu Alpha https://alpha.com --porcelain`
+    Then save STDOUT as {ITEM_ID_1}
+
+    When I run `wp menu item add-custom sidebar-menu Beta https://beta.com --porcelain`
+    Then save STDOUT as {ITEM_ID_2}
+
+    When I run `wp menu item add-custom sidebar-menu Gamma https://gamma.com --porcelain`
+    Then save STDOUT as {ITEM_ID_3}
+
+    When I run `wp menu item list sidebar-menu --fields=type,title,position,link`
+    Then STDOUT should be a table containing rows:
+      | type   | title | position | link               |
+      | custom | Alpha | 1        | https://alpha.com  |
+      | custom | Beta  | 2        | https://beta.com   |
+      | custom | Gamma | 3        | https://gamma.com  |
+
+    When I run `wp menu item update {ITEM_ID_3} --position=1`
+    Then STDOUT should be:
+      """
+      Success: Menu item updated.
+      """
+
+    When I run `wp menu item list sidebar-menu --fields=type,title,position,link`
+    Then STDOUT should be a table containing rows:
+      | type   | title | position | link               |
+      | custom | Gamma | 1        | https://gamma.com  |
+      | custom | Alpha | 2        | https://alpha.com  |
+      | custom | Beta  | 3        | https://beta.com   |
+
+    When I run `wp menu item update {ITEM_ID_1} --position=3`
+    Then STDOUT should be:
+      """
+      Success: Menu item updated.
+      """
+
+    When I run `wp menu item list sidebar-menu --fields=type,title,position,link`
+    Then STDOUT should be a table containing rows:
+      | type   | title | position | link               |
+      | custom | Gamma | 1        | https://gamma.com  |
+      | custom | Beta  | 2        | https://beta.com   |
+      | custom | Alpha | 3        | https://alpha.com  |
+
   Scenario: Get menu item details
     When I run `wp menu create "Sidebar Menu"`
     Then STDOUT should not be empty

src/Menu_Item_Command.php

@@ -587,7 +587,8 @@ private function add_or_update_item( $method, $type, $args, $assoc_args ) {
 			$menu_item_obj = wp_setup_nav_menu_item( $menu_item_obj );
 
 			// Correct the menu position if this was the first item. See https://core.trac.wordpress.org/ticket/28140
-			$position = ( 0 === $menu_item_obj->menu_order ) ? 1 : $menu_item_obj->menu_order;
+			$position     = ( 0 === $menu_item_obj->menu_order ) ? 1 : $menu_item_obj->menu_order;
+			$old_position = $position;
 
 			$default_args = [
 				'position'    => $position,
@@ -634,7 +635,67 @@ private function add_or_update_item( $method, $type, $args, $assoc_args ) {
 		}
 
 		$menu_item_args['menu-item-type'] = $type;
-		$result                           = wp_update_nav_menu_item( $menu->term_id, $menu_item_db_id, $menu_item_args );
+
+		// Reorder other menu items when the position changes on update.
+		if ( 'update' === $method ) {
+			$new_position = (int) $menu_item_args['menu-item-position'];
+			if ( $new_position > 0 ) {
+				// Fetch all menu items sorted by their raw menu_order to determine
+				// normalized (1-indexed) ranks, since wp_get_nav_menu_items(ARRAY_A)
+				// normalises menu_order to 1,2,3… which may differ from the raw DB values.
+				$sorted_items = get_posts(
+					[
+						'post_type'   => 'nav_menu_item',
+						'numberposts' => -1,
+						'orderby'     => 'menu_order',
+						'order'       => 'ASC',
+						'post_status' => 'any',
+						'tax_query'   => [
+							[
+								'taxonomy' => 'nav_menu',
+								'field'    => 'term_taxonomy_id',
+								'terms'    => $menu->term_taxonomy_id,
+							],
+						],
+					]
+				);
+
+				// Find the 1-indexed normalized rank of the item being moved.
+				$old_position_normalized = 0;
+				foreach ( $sorted_items as $idx => $sorted_item ) {
+					if ( (int) $sorted_item->ID === (int) $menu_item_db_id ) {
+						$old_position_normalized = $idx + 1;
+						break;
+					}
+				}
+
+				if ( $old_position_normalized > 0 && $new_position !== $old_position_normalized ) {
+					if ( $new_position < $old_position_normalized ) {
+						// Moving up: items at 0-indexed [new_pos-1, old_pos-2] shift down by +1.
+						for ( $i = $new_position - 1; $i <= $old_position_normalized - 2; $i++ ) {
+							wp_update_post(
+								[
+									'ID'         => $sorted_items[ $i ]->ID,
+									'menu_order' => $i + 2,
+								]
+							);
+						}
+					} else {
+						// Moving down: items at 0-indexed [old_pos, new_pos-1] shift up by -1.
+						for ( $i = $old_position_normalized; $i <= $new_position - 1; $i++ ) {
+							wp_update_post(
+								[
+									'ID'         => $sorted_items[ $i ]->ID,
+									'menu_order' => $i,
+								]
+							);
+						}
+					}
+				}
+			}
+		}
+
+		$result = wp_update_nav_menu_item( $menu->term_id, $menu_item_db_id, $menu_item_args );
 
 		if ( is_wp_error( $result ) ) {
 			WP_CLI::error( $result->get_error_message() );