Treat 30X response without Location header field as error

This is required to make segmented download work.

src/HttpResponse.cc

@@ -105,6 +105,10 @@ void HttpResponse::validateResponse() const
   case 303: // See Other
   case 307: // Temporary Redirect
   case 308: // Permanent Redirect
+    if (!httpHeader_->defined(HttpHeader::LOCATION)) {
+      throw DL_ABORT_EX2(fmt(EX_LOCATION_HEADER_REQUIRED, statusCode),
+                         error_code::HTTP_PROTOCOL_ERROR);
+    }
     return;
   }
   if (statusCode >= 400) {

src/HttpResponseCommand.cc

@@ -231,11 +231,10 @@ bool HttpResponseCommand::executeInternal()
 #endif // ENABLE_MESSAGE_DIGEST
   }
 
-  if (statusCode == 404) {
-    grp->increaseAndValidateFileNotFoundCount();
-    return skipResponseBody(std::move(httpResponse));
-  }
-  if (statusCode >= 400 || statusCode == 304 || httpResponse->isRedirect()) {
+  if(statusCode >= 300) {
+    if(statusCode == 404) {
+      grp->increaseAndValidateFileNotFoundCount();
+    }
     return skipResponseBody(std::move(httpResponse));
   }
 

test/HttpResponseTest.cc

@@ -362,7 +362,14 @@ void HttpResponseTest::testValidateResponse()
   httpResponse.setHttpHeader(make_unique<HttpHeader>());
   httpResponse.getHttpHeader()->setStatusCode(301);
 
-  // It is fine without Location header
+  try {
+    httpResponse.validateResponse();
+    CPPUNIT_FAIL("exception must be thrown.");
+  } catch(Exception& e) {
+    // success
+  }
+
+  httpResponse.getHttpHeader()->put(HttpHeader::LOCATION, "http://a/b");
   httpResponse.validateResponse();
 
   httpResponse.getHttpHeader()->setStatusCode(201);