XML HTTP error responses set a 200 error code instead of a 500

This patch does not work as advertised: it only sends a 500 status code when Drupal is configured to display errors. I'd expect a 500 response regardless of the error level.

The patch in #2688999 seems to take care of this point, so in combination these two should work. Note the patch in #2688999 by itself is not enough to deal with the issue describe here. For example:

http_response_code(500);
$response = new Response();
$response->send();

Above snippet will result in a 200 OK response message.

The new patch combines the fix for AJAX error handling with the patch from #2688999. Since that one has the tag "needs work", it's only fair to say this one needs work too :)

I don't think we should combine those patches because they are separate issues. Why not try to fix the error handling specifically for AJAX requests, something like:

  if (\Drupal::hasRequest() && \Drupal::request()->isXmlHttpRequest()) {
    if ($fatal) {
+     http_response_code(500);

      if (error_displayable($error)) {
        // When called from JavaScript, simply output the error message.
        // Should not translate the string to avoid errors producing more errors.
        $response->setContent(SafeMarkup::format('%type: @message in %function (line %line of %file).', $error));
+       $response->setStatusCode(500);
        $response->send();
      }
      exit;
    }

That way, this patch could be merged into core without depending on #2688999.

Thank you, everyone, for working on this. I think this work should be postponed on #2688999: Default all responses to 500 before any code is run so PHP will throw 500's on FATAL errors because setting http_response_code(500) will be redundant after #2688999 is finished.

I am surprised the #11 patch applies because it is targeting a top-level web/ directory that does not exist in Drupal core.

@jsst For your reference, please read about the core gates for reviewing purposes. In particular, this one would need a test.

The related issue #2688999: Default all responses to 500 before any code is run so PHP will throw 500's on FATAL errors has got stuck. I think we should continue here as regardless of what happens in #2688999: Default all responses to 500 before any code is run so PHP will throw 500's on FATAL errors fixing this particular bug is a good idea.

Here's a fix plus a test so we don't break this in the future.

+1

+++ b/core/includes/errors.inc
@@ -199,11 +199,15 @@ function _drupal_log_error($error, $fatal = FALSE) {
+      else {
+        $response->setStatusCode(500);
+      }
+      $response->send();

good to send the response back, if the error display isn't on.

Pretty sure the Drupal\Tests\field_layout\FunctionalJavascript\FieldLayoutTest fail is regular random JS test fail. Passes locally.

Having the same issue on core 10.1.0 and patch #19 it's not applying, so rerolling this patch to apply on 10.1.0