[HttpFoundation] Fix base URI detection on IIS with UrlRewriteModule

Author: derrabus

Request.php

@@ -246,6 +246,9 @@ class Request
         self::HEADER_X_FORWARDED_PREFIX => 'X_FORWARDED_PREFIX',
     ];
 
+    /** @var bool */
+    private $isIisRewrite = false;
+
     /**
      * @param array                $query      The GET parameters
      * @param array                $request    The POST parameters
@@ -1805,11 +1808,10 @@ protected function prepareRequestUri()
     {
         $requestUri = '';
 
-        if ('1' == $this->server->get('IIS_WasUrlRewritten') && '' != $this->server->get('UNENCODED_URL')) {
+        if ($this->isIisRewrite() && '' != $this->server->get('UNENCODED_URL')) {
             // IIS7 with URL Rewrite: make sure we get the unencoded URL (double slash problem)
             $requestUri = $this->server->get('UNENCODED_URL');
             $this->server->remove('UNENCODED_URL');
-            $this->server->remove('IIS_WasUrlRewritten');
         } elseif ($this->server->has('REQUEST_URI')) {
             $requestUri = $this->server->get('REQUEST_URI');
 
@@ -2012,7 +2014,13 @@ private function setPhpDefaultLocale(string $locale): void
      */
     private function getUrlencodedPrefix(string $string, string $prefix): ?string
     {
-        if (!str_starts_with(rawurldecode($string), $prefix)) {
+        if ($this->isIisRewrite()) {
+            // ISS with UrlRewriteModule might report SCRIPT_NAME/PHP_SELF with wrong case
+            // see https://github.com/php/php-src/issues/11981
+            if (0 !== stripos(rawurldecode($string), $prefix)) {
+                return null;
+            }
+        } elseif (!str_starts_with(rawurldecode($string), $prefix)) {
             return null;
         }
 
@@ -2145,4 +2153,20 @@ private function normalizeAndFilterClientIps(array $clientIps, string $ip): arra
         // Now the IP chain contains only untrusted proxies and the client IP
         return $clientIps ? array_reverse($clientIps) : [$firstTrustedIp];
     }
+
+    /**
+     * Is this IIS with UrlRewriteModule?
+     *
+     * This method consumes, caches and removed the IIS_WasUrlRewritten env var,
+     * so we don't inherit it to sub-requests.
+     */
+    private function isIisRewrite(): bool
+    {
+        if (1 === $this->server->getInt('IIS_WasUrlRewritten')) {
+            $this->isIisRewrite = true;
+            $this->server->remove('IIS_WasUrlRewritten');
+        }
+
+        return $this->isIisRewrite;
+    }
 }

Tests/RequestTest.php

@@ -1850,6 +1850,62 @@ public static function getBaseUrlData()
         ];
     }
 
+    /**
+     * @dataProvider baseUriDetectionOnIisWithRewriteData
+     */
+    public function testBaseUriDetectionOnIisWithRewrite(array $server, string $expectedBaseUrl, string $expectedPathInfo)
+    {
+        $request = new Request([], [], [], [], [], $server);
+
+        self::assertSame($expectedBaseUrl, $request->getBaseUrl());
+        self::assertSame($expectedPathInfo, $request->getPathInfo());
+    }
+
+    public static function baseUriDetectionOnIisWithRewriteData(): \Generator
+    {
+        yield 'No rewrite' => [
+            [
+                'PATH_INFO' => '/foo/bar',
+                'PHP_SELF' => '/routingtest/index.php/foo/bar',
+                'REQUEST_URI' => '/routingtest/index.php/foo/bar',
+                'SCRIPT_FILENAME' => 'C:/Users/derrabus/Projects/routing-test/public/index.php',
+                'SCRIPT_NAME' => '/routingtest/index.php',
+            ],
+            '/routingtest/index.php',
+            '/foo/bar',
+        ];
+
+        yield 'Rewrite with correct case' => [
+            [
+                'IIS_WasUrlRewritten' => '1',
+                'PATH_INFO' => '/foo/bar',
+                'PHP_SELF' => '/routingtest/index.php/foo/bar',
+                'REQUEST_URI' => '/routingtest/foo/bar',
+                'SCRIPT_FILENAME' => 'C:/Users/derrabus/Projects/routing-test/public/index.php',
+                'SCRIPT_NAME' => '/routingtest/index.php',
+                'UNENCODED_URL' => '/routingtest/foo/bar',
+            ],
+            '/routingtest',
+            '/foo/bar',
+        ];
+
+        // ISS with UrlRewriteModule might report SCRIPT_NAME/PHP_SELF with wrong case
+        // see https://github.com/php/php-src/issues/11981
+        yield 'Rewrite with case mismatch' => [
+            [
+                'IIS_WasUrlRewritten' => '1',
+                'PATH_INFO' => '/foo/bar',
+                'PHP_SELF' => '/routingtest/index.php/foo/bar',
+                'REQUEST_URI' => '/RoutingTest/foo/bar',
+                'SCRIPT_FILENAME' => 'C:/Users/derrabus/Projects/routing-test/public/index.php',
+                'SCRIPT_NAME' => '/routingtest/index.php',
+                'UNENCODED_URL' => '/RoutingTest/foo/bar',
+            ],
+            '/RoutingTest',
+            '/foo/bar',
+        ];
+    }
+
     /**
      * @dataProvider urlencodedStringPrefixData
      */