useragent test

          "outgoing user-agent: line carries the exact original value, unsplit");

}

// A second request on the SAME keep-alive connection must not see the first

// request's User-Agent lingering alongside its own -- HttpRequest::parseH1()

// deliberately does getHeaderData() before setHeaderData() per-line (see its

// own comment) so a header genuinely repeated *within one request* (multiple

// Cookie: lines) appends rather than clobbers, but that lookup can't tell

// "repeated within this request" apart from "left over from the request

// before it" on a reused connection unless something clears state in

// between. Real browsers reuse one connection for many sequential requests;

// curl-style one-request-per-connection testing (like the two tests above)

// never exercises this at all -- which is exactly why it went unnoticed

// until a strict upstream (observed live: Home Assistant's aiohttp) started

// rejecting the accumulated duplicate outright.

void testKeepAliveDoesNotAccumulateHeaders(int port) {

    auto sock = std::make_unique<netplus::tcp>();

    rawtcp::connectLocal(*sock, port);

    auto doRequest = [&](const std::string &ua) {

        std::ostringstream req;

        req << "GET /ua-echo HTTP/1.1\r\n"

            << "Host: 127.0.0.1:" << port << "\r\n"

            << "User-Agent: " << ua << "\r\n"

            << "Connection: keep-alive\r\n"

            << "\r\n";

        rawtcp::sendAllOrThrow(*sock, req.str());

        HttpResponse res;

        rawReadHeadersAndParse(*sock, res);

        return res;

    };

    HttpResponse first = doRequest("FirstAgent/1.0");

    check(headerValue(first, "x-ua-count") == "1",

          "keep-alive request #1 -- server sees exactly one Value");

    check(headerValue(first, "x-ua-echo") == "FirstAgent/1.0",

          "keep-alive request #1 -- value matches what was sent");

    HttpResponse second = doRequest("SecondAgent/2.0");

    sock->close();

    check(headerValue(second, "x-ua-count") == "1",

          "keep-alive request #2 on the SAME connection -- still exactly one Value, "

          "not two (request #1's stale value must not linger)");

    check(headerValue(second, "x-ua-echo") == "SecondAgent/2.0",

          "keep-alive request #2 -- value is request #2's own, not request #1's "

          "leftover joined with it");

}

} // namespace

int main() {

        testSemicolonHeavyUserAgentNotSplit(port);

        testPrintHeaderSingleUserAgentLine();

        testKeepAliveDoesNotAccumulateHeaders(port);

    } catch (HTTPException &e) {

        std::cerr << "HTTPException: " << e.what() << std::endl;