fix: distinguish unchanged enrollment meta

Author: chubes4

providers/class-two-factor-totp.php

@@ -331,7 +331,7 @@ public function rest_begin_enrollment( $request ) {
 			'expires_at' => $expires_at,
 		);
 
-		if ( ! update_user_meta( $user->ID, self::PENDING_ENROLLMENT_META_KEY, $pending ) ) {
+		if ( ! update_user_meta( $user->ID, self::PENDING_ENROLLMENT_META_KEY, $pending ) && get_user_meta( $user->ID, self::PENDING_ENROLLMENT_META_KEY, true ) !== $pending ) {
 			return new WP_Error( 'db_error', __( 'Unable to begin Two Factor Authentication enrollment.', 'two-factor' ), array( 'status' => 500 ) );
 		}
 

tests/providers/class-two-factor-totp-rest-api.php

@@ -349,6 +349,40 @@ public function test_begin_and_confirm_server_owned_enrollment() {
 		Two_Factor_Totp::set_time( null );
 	}
 
+	/**
+	 * An unchanged pending enrollment value is not a database error.
+	 *
+	 * @covers Two_Factor_Totp::rest_begin_enrollment
+	 */
+	public function test_begin_enrollment_accepts_unchanged_meta_update() {
+		wp_set_current_user( self::$admin_id );
+
+		$filter = function ( $check, $user_id, $meta_key, $meta_value ) use ( &$filter ) {
+			if ( Two_Factor_Totp::PENDING_ENROLLMENT_META_KEY !== $meta_key ) {
+				return $check;
+			}
+
+			remove_filter( 'update_user_metadata', $filter );
+			update_user_meta( $user_id, $meta_key, $meta_value );
+
+			return false;
+		};
+		add_filter( 'update_user_metadata', $filter, 10, 4 );
+
+		$request = new WP_REST_Request( 'POST', '/' . Two_Factor_Core::REST_NAMESPACE . '/totp/enrollment' );
+		$request->set_body_params( array( 'user_id' => self::$admin_id ) );
+		$response = rest_do_request( $request );
+		$data     = $response->get_data();
+
+		remove_filter( 'update_user_metadata', $filter );
+
+		$this->assertSame( 200, $response->get_status() );
+		$pending = get_user_meta( self::$admin_id, Two_Factor_Totp::PENDING_ENROLLMENT_META_KEY, true );
+		$this->assertSame( $data['secret'], $pending['key'] );
+
+		delete_user_meta( self::$admin_id, Two_Factor_Totp::PENDING_ENROLLMENT_META_KEY );
+	}
+
 	/**
 	 * A newer enrollment replaces the previous pending secret.
 	 *