Content-length incorrect and response truncated in web servers

I wonder if this is a duplicate of 🐛 Incorrect content-length header breaks HTTP/2 with net::err_http2_protocol_error Active , with the same root cause.

It's similar but i have not the err_http2_protocolol_error, and the solutions didn't work for my problem.

After Drupal update to 10.2.5 a XML sync with a other system was broken.
With the patch above

- $response->headers->set('Content-Length', strlen($content), TRUE);
+ $response->headers->set('Content-Length', strlen($content)+2, TRUE);

AND set ' Header always unset Content-Length ' in the .htaccess

And things are working again :-}

https://www.drupal.org/project/drupal/issues/3419024#comment-15539269 🐛 Incorrect content-length header breaks HTTP/2 with net::err_http2_protocol_error Active

Thanks @Carlitus for reporting and make a solution.

So this is a duplicate.

Why is a duplicate?

Your welcome @MLZR, I am glad that my solution has been able to help more people.

They have the same workaround.

@cilifen, the workaround it's copied from here, you can see that @MLZR links to this issue.

We have two or three issues where the content length header is wrong due to a change in Drupal core.

What do you recommend? should I put this MR in the other issue?

This isn't the correct fix though, as can be seen by the failing tests - we need to figure out why this is two characters out sometimes. Are you also using nginx, or does this happen on Apache as well?

We need someone who can reproduce this to log the response at the point that we calculate Content-Length, and compare it to the response that nginx sends out, and see what the actual difference is - presumably two extra characters are present, but what are they?

I have two configured Apache servers; one with FastCGI and another with php-fpm. On the server with php-fpm I'm getting no content type served from files in "/system/files"; presumably the same issue that others are complaining about. Making changes to the recommended above files does nothing; so this is not a correct fix. I hope this helps?

@marc5000 i think this is another issue.

There's another issue in the queue which sounds similar, where the issue has been whitespace before the opening <?php PHP tag, it would be worth checking for that. Will link the other issue when I find it.

Linking the issue mentioned by @catch above.

@catch this reminds me of #3225466: Blank line in .module file causes blank line in HTML output → which I debugged by adding code to ModuleHandler::loadInclude to detect which file caused the issue - I wonder if that should be a standard core feature.

Given the number of people running into this that seems worth looking into yeah.

yes, thats it. It's in bat_module, without the whitespace and also without this patch all works well.
https://www.drupal.org/project/bat_api/issues/3411329#comment-15590410 🐛 With Drupal 10.2.0 the rest api doesn't return a valid json Needs work

Thanks!

Changes are made on on 11.x (our main development branch) first, and are then back ported as needed according to our policies.

I think i can close the issue, because i was another module that cause this.