cgi httpd bug when receiving a HEAD request

[jonatjano]

The bug exists in both embedded_httpd_threads and embedded_httpd_process

context : my program is executed on a shared server were http(s) requests are redirected by a Gateway which I have no control on

when using arsd.cgi to receive a request I found that HEAD requests always responded by 502 Bad Gateway while any other method worked as expected, after investigating I found that the only difference is in Cgi.close where when receiving HEAD, the outputBuffer is not written (as expected for HEAD requests)
But that writing in close is made with isAll = true which seems to be required even for HEAD requests

adding cgi.write("", true, false) to my code solved the issue

void handler(Cgi cgi)
{
        writeln(cgi.requestMethod.to!string, cgi.requestUri);

        switch (cgi.pathInfo)
        {
                case "/":
                        if (cgi.requestMethod == Cgi.RequestMethod.HEAD) {
                                cgi.setResponseStatus(200);
                                cgi.write("", true, false); // this call solves the issue, in the case of other method, it is made inside of cgi.close
                        } else if (cgi.requestMethod == Cgi.RequestMethod.GET) {
                                cgi.setResponseStatus(200);
                                cgi.setResponseContentType("text/html");
                                cgi.write("Hello, World!");
                        } else {
                                cgi.setResponseStatus("404 Not found");
                                cgi.write("Requested page not found.");
                        }
                        break;
                default:
                        cgi.setResponseStatus("404 Not found");
                        cgi.write("Requested page not found.");
                        break;
        }
        cgi.close;
}

[adamdruppe]

i'll have to take a look, make sure the Content-Length is set right. Cuz I'm pretty sure HEAD is supposed to set that, but not actually send the content.

[jonatjano]

Setting the Content-Length manually with cgi.header("Content-Length: 0"); do not solve the issue

[adamdruppe]

it needs to flush the buffers with cgi.write does, but the headers still need to be set as if it was allw ritten

i'll get to it later, i gotta fdo soemthing else rn. im p sure the problem is just that the header buffers aren't flushed but they also need to be set right

[adamdruppe]

see cgi.close calls write(null, false, false) so swapping to true might work if the other headers are right

[adamdruppe]

Sorry, I got distracted and just tested this now but indeed this very small change does seem to do the job:

6b4cc44

[adamdruppe]

I did a v10.9.10 hotfix released for this and a couple other small issues.