Added test that improperly prefixed headers are not returned by marsh…

…alHeadersFromSapi

test/ServerRequestFactoryTest.php

@@ -60,6 +60,23 @@ public function testMarshalsExpectedHeadersFromServerArray()
         $this->assertSame($expected, marshalHeadersFromSapi($server));
     }
 
+    public function testMarshalInvalidHeadersStrippedFromServerArray()
+    {
+        $server = [
+            'COOKIE' => 'COOKIE',
+            'HTTP_AUTHORIZATION' => 'token',
+            'MD5' => 'CONTENT-MD5',
+            'CONTENT_LENGTH' => 'UNSPECIFIED',
+        ];
+
+        //Headers that don't begin with HTTP_ or CONTENT_ will not be returned
+        $expected = [
+            'authorization' => 'token',
+            'content-length' => 'UNSPECIFIED',
+        ];
+        $this->assertSame($expected, marshalHeadersFromSapi($server));
+    }
+
     public function testMarshalsVariablesPrefixedByApacheFromServerArray()
     {
         // Non-prefixed versions will be preferred