Fix #3038

src/Bridge/Symfony/Bundle/Test/Client.php

@@ -92,7 +92,7 @@ public function request(string $method, string $url, array $options = []): Respo
 
         $server = [];
         // Convert headers to a $_SERVER-like array
-        foreach ($options['headers'] as $key => $value) {
+        foreach (self::extractHeaders($options) as $key => $value) {
             if ('content-type' === $key) {
                 $server['CONTENT_TYPE'] = $value[0] ?? '';
 
@@ -212,4 +212,25 @@ public function enableReboot(): void
     {
         $this->kernelBrowser->enableReboot();
     }
+
+    /**
+     * Extract headers depending on the symfony/http-client version being used.
+     */
+    private static function extractHeaders(array $options): array
+    {
+        if (!isset($options['normalized_headers'])) {
+            return $options['headers'];
+        }
+
+        $headers = [];
+
+        foreach ($options['normalized_headers'] as $key => $values) {
+            foreach ($values as $value) {
+                [, $value] = explode(': ', $value, 2);
+                $headers[$key][] = $value;
+            }
+        }
+
+        return $headers;
+    }
 }