Throw exception when header is invalid

Fixes #180 - infinite recursion

Author: michalbundyra

src/Headers.php

@@ -472,6 +472,10 @@ protected function lazyLoadHeader($index, $isGeneric = false)
         try {
             $headers = $class::fromString($current['line']);
         } catch (Exception\InvalidArgumentException $exception) {
+            if ($isGeneric) {
+                throw $exception;
+            }
+
             return $this->lazyLoadHeader($index, true);
         }
         if (is_array($headers)) {

test/HeadersTest.php

@@ -315,4 +315,14 @@ public function testCRLFAttack()
         $this->expectException(RuntimeException::class);
         Headers::fromString("Fake: foo-bar\r\n\r\nevilContent");
     }
+
+    public function testThrowExceptionOnInvalidHeader()
+    {
+        $headers = new Headers();
+        $headers->addHeaderLine('Location', "/mail\r\ntest");
+
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('Invalid header value detected');
+        $headers->get('Location');
+    }
 }