Fixes a Composer script error and an issue where WP REST API urls would be broken on newly created sites.

For more information see https://docs.pantheon.io/release-notes/2025/05/wordpress-composer-managed-1-33-0

Author: jazzsequence

CHANGELOG.md

@@ -1,3 +1,7 @@
+### v1.33.0 (2025-05-08)
+* Fixes an issue where we were running `maybe-add-symlinks` but the script didn't exist. ([#183](https://github.com/pantheon-systems/wordpress-composer-managed/pull/183))
+* Fixes an issue where WP REST API urls would break on new sites before "pretty permalink" structure was set. ([#186](https://github.com/pantheon-systems/wordpress-composer-managed/pull/186))
+
 ### v1.32.5 (2025-02-10)
 * Adds the `maybe-install-symlinks` Composer script to `post-update-cmd` hook. This ensures that symlinks are created (and the `web/index.php` file is re-created) after a `composer update`. ([#175](https://github.com/pantheon-systems/wordpress-composer-managed/pull/175))
 

web/app/mu-plugins/filters.php

@@ -3,7 +3,7 @@
  * Plugin Name: Pantheon WordPress Filters
  * Plugin URI:   https://github.com/pantheon-systems/wordpress-composer-managed
  * Description:  Filters for Composer-managed WordPress sites on Pantheon.
- * Version:      1.2.2
+ * Version:      1.2.3
  * Author:       Pantheon Systems
  * Author URI:   https://pantheon.io/
  * License:      MIT License
@@ -235,3 +235,150 @@ function __rebuild_url_from_parts( array $parts ) : string {
 		( isset( $parts['fragment'] ) ? str_replace( '/', '', "#{$parts['fragment']}" ) : '' )
 	);
 }
+
+/**
+ * REST API Plain Permalink Fix
+ *
+ * Extracts the REST API endpoint from a potentially malformed path.
+ * Handles cases like /wp-json/v2/posts or /wp-json/wp/v2/posts.
+ *
+ * @since 1.2.3
+ * @param string $path The URL path component.
+ * @return string The extracted endpoint (e.g., /v2/posts) or '/'.
+ */
+function __extract_rest_endpoint( string $path ) : string {
+	$rest_route = '/'; // Default to base route
+	$wp_json_pos = strpos( $path, '/wp-json/' );
+
+    if ( $wp_json_pos === false ) {
+        return $rest_route; // Return base if /wp-json/ not found
+    }
+
+    $extracted_route = substr( $path, $wp_json_pos + strlen( '/wp-json' ) ); // Get everything after /wp-json
+    // Special case: Handle the originally reported '/wp-json/wp/' malformation
+    if ( strpos( $extracted_route, 'wp/' ) === 0 ) {
+        $extracted_route = substr( $extracted_route, strlen( 'wp' ) ); // Remove the extra 'wp'
+    }
+    // Ensure the extracted route starts with a slash
+    if ( ! $extracted_route && $extracted_route[0] !== '/' ) {
+        $extracted_route = '/' . $extracted_route;
+    }
+    $rest_route = $extracted_route ?: '/'; // Use extracted route or default to base
+
+	return $rest_route;
+}
+
+/**
+ * Builds the correct plain permalink REST URL.
+ *
+ * @since 1.2.3
+ * @param string $endpoint The REST endpoint (e.g., /v2/posts).
+ * @param string|null $query_str The original query string (or null).
+ * @param string|null $fragment The original fragment (or null).
+ * @return string The fully constructed plain permalink REST URL.
+ */
+function __build_plain_rest_url( string $endpoint, ?string $query_str, ?string $fragment ) : string {
+	$home_url = home_url(); // Should be https://.../wp
+	// Ensure endpoint starts with /
+	$endpoint = '/' . ltrim( $endpoint, '/' );
+	// Construct the base plain permalink URL
+	$correct_url = rtrim( $home_url, '/' ) . '/?rest_route=' . $endpoint;
+
+	// Append original query parameters (if any, besides rest_route)
+	if ( ! empty( $query_str ) ) {
+		parse_str( $query_str, $query_params );
+		unset( $query_params['rest_route'] ); // Ensure no leftover rest_route
+		if ( ! empty( $query_params ) ) {
+			// Check if $correct_url already has '?' (it should)
+			$correct_url .= '&' . http_build_query( $query_params );
+		}
+	}
+	// Append fragment if present
+	if ( ! empty( $fragment ) ) {
+		$correct_url .= '#' . $fragment;
+	}
+
+	// Use normalization helper if available
+	if ( function_exists( __NAMESPACE__ . '\\__normalize_wp_url' ) ) {
+		return __normalize_wp_url( $correct_url );
+	}
+
+    return $correct_url; // Return without full normalization as fallback
+}
+
+/**
+ * Corrects generated REST API URL when plain permalinks are active but WordPress
+ * incorrectly generates a pretty-permalink-style path. Forces the URL
+ * back to the expected ?rest_route= format using helpers.
+ *
+ * @since 1.2.3
+ * @param string $url The potentially incorrect REST URL generated by WP.
+ * @return string The corrected REST URL in plain permalink format.
+ */
+function filter_force_plain_rest_url_format( string $url ) : string {
+	$parsed_url = parse_url($url);
+
+	// Check if it looks like a pretty permalink URL (has /wp-json/ in path)
+	// AND lacks the ?rest_route= query parameter.
+	$has_wp_json_path = isset( $parsed_url['path'] ) && strpos( $parsed_url['path'], '/wp-json/' ) !== false;
+	$has_rest_route_query = isset( $parsed_url['query'] ) && strpos( $parsed_url['query'], 'rest_route=' ) !== false;
+
+	if ( $has_wp_json_path && ! $has_rest_route_query ) {
+		// It's using a pretty path format when it shouldn't be.
+		$endpoint = __extract_rest_endpoint( $parsed_url['path'] );
+		return __build_plain_rest_url( $endpoint, $parsed_url['query'] ?? null, $parsed_url['fragment'] ?? null );
+	}
+
+	// If the URL didn't match the problematic pattern, return it normalized.
+    return __normalize_wp_url($url);
+}
+
+/**
+ * Handles incoming requests using a pretty REST API path format when plain
+ * permalinks are active. It sets the correct 'rest_route' query variable
+ * internally instead of performing an external redirect.
+ *
+ * @since 1.2.3
+ * @param \WP $wp The WP object, passed by reference.
+ */
+function handle_pretty_rest_request_on_plain_permalinks( \WP &$wp ) {
+	// Only run if it's not an admin request. Permalink structure checked by the hook caller.
+	if ( is_admin() ) {
+		return;
+	}
+
+	// Use REQUEST_URI as it's more reliable for the raw request path before WP parsing.
+	$request_uri = $_SERVER['REQUEST_URI'] ?? '';
+	// Get the path part before any query string.
+	$request_path = strtok($request_uri, '?');
+
+	// Define the pretty permalink base path we expect if pretty permalinks *were* active.
+	$home_url_path = rtrim( parse_url( home_url(), PHP_URL_PATH ) ?: '', '/' ); // e.g., /wp
+	$pretty_rest_path_base = $home_url_path . '/wp-json/'; // e.g., /wp/wp-json/
+
+	// Check if the actual request path starts with this pretty base.
+	if ( strpos( $request_path, $pretty_rest_path_base ) === 0 ) {
+		// Extract the endpoint part *after* the base.
+		$endpoint = substr( $request_path, strlen( $pretty_rest_path_base ) );
+		// Ensure endpoint starts with a slash, default to base if empty.
+		$endpoint = '/' . ltrim($endpoint, '/');
+		// If the result is just '/', set it back to empty string for root endpoint ?rest_route=/
+		$endpoint = ($endpoint === '/') ? '' : $endpoint;
+
+		// Check if rest_route is already set (e.g., from query string), if so, don't overwrite.
+		// This prevents conflicts if someone manually crafts a URL like /wp/wp-json/posts?rest_route=/users
+		if ( ! isset( $wp->query_vars['rest_route'] ) ) {
+			// Directly set the query variable for the REST API.
+			$wp->query_vars['rest_route'] = $endpoint;
+
+		}
+		// No redirect, no exit. Let WP continue processing with the modified query vars.
+	}
+}
+
+// Only add the REST URL *generation* fix and the request handler if plain permalinks are enabled.
+if ( ! get_option('permalink_structure') ) {
+	add_filter('rest_url', __NAMESPACE__ . '\\filter_force_plain_rest_url_format', 10, 1);
+	// Hook the request handling logic to parse_request. Pass the $wp object by reference.
+	add_action('parse_request', __NAMESPACE__ . '\\handle_pretty_rest_request_on_plain_permalinks', 1, 1);
+}