From: Tim Starling <tstarling@wikimedia.org>
Date: Tue, 10 Sep 2019 06:26:53 +0000 (+1000)
Subject: REST: Properly handle HEAD requests
X-Git-Tag: 1.34.0-rc.0~179^2
X-Git-Url: https://git.cyclocoop.org/%7B%24www_url%7Dadmin/compta/exercices/journal.php?a=commitdiff_plain;h=9911a3605019806e972a26f5d19cf9ac8c16c401;p=lhc%2Fweb%2Fwiklou.git

REST: Properly handle HEAD requests

Just handle a HEAD request as a GET request, if no specific HEAD handler
exists. This is simple and similar to what the rest of MediaWiki does in
response to a HEAD request.

Bug: T226043
Change-Id: I7b2bd657c20b56844459874131a3d85fabe7db3d
---

diff --git a/includes/Rest/Router.php b/includes/Rest/Router.php
index 1c5f66b2be..6821d89c27 100644
--- a/includes/Rest/Router.php
+++ b/includes/Rest/Router.php
@@ -233,15 +233,22 @@ class Router {
 			);
 		}
 
+		$requestMethod = $request->getMethod();
 		$matchers = $this->getMatchers();
-		$matcher = $matchers[$request->getMethod()] ?? null;
+		$matcher = $matchers[$requestMethod] ?? null;
 		$match = $matcher ? $matcher->match( $relPath ) : null;
 
+		// For a HEAD request, execute the GET handler instead if one exists.
+		// The webserver will discard the body.
+		if ( !$match && $requestMethod === 'HEAD' && isset( $matchers['GET'] ) ) {
+			$match = $matchers['GET']->match( $relPath );
+		}
+
 		if ( !$match ) {
 			// Check for 405 wrong method
 			$allowed = [];
 			foreach ( $matchers as $allowedMethod => $allowedMatcher ) {
-				if ( $allowedMethod === $request->getMethod() ) {
+				if ( $allowedMethod === $requestMethod ) {
 					continue;
 				}
 				if ( $allowedMatcher->match( $relPath ) ) {
@@ -251,7 +258,7 @@ class Router {
 			if ( $allowed ) {
 				$response = $this->responseFactory->createLocalizedHttpError( 405,
 					( new MessageValue( 'rest-wrong-method' ) )
-						->textParams( $request->getMethod() )
+						->textParams( $requestMethod )
 						->commaListParams( $allowed )
 						->numParams( count( $allowed ) )
 				);
diff --git a/tests/phpunit/unit/includes/Rest/RouterTest.php b/tests/phpunit/unit/includes/Rest/RouterTest.php
index 9f51371a55..58039ea846 100644
--- a/tests/phpunit/unit/includes/Rest/RouterTest.php
+++ b/tests/phpunit/unit/includes/Rest/RouterTest.php
@@ -55,6 +55,16 @@ class RouterTest extends \MediaWikiUnitTestCase {
 		$this->assertSame( 'GET', $response->getHeaderLine( 'Allow' ) );
 	}
 
+	public function testHeadToGet() {
+		$request = new RequestData( [
+			'uri' => new Uri( '/rest/user/joe/hello' ),
+			'method' => 'HEAD'
+		] );
+		$router = $this->createRouter( $request );
+		$response = $router->execute( $request );
+		$this->assertSame( 200, $response->getStatusCode() );
+	}
+
 	public function testNoMatch() {
 		$request = new RequestData( [ 'uri' => new Uri( '/rest/bogus' ) ] );
 		$router = $this->createRouter( $request );