Array to string conversion error for HTTP/2 headers

[gwilym]

Please answer these questions before submitting your issue. Thanks!

1. What did you do? If possible, provide a simple script for reproducing the error.

This is related to a fix in LaravelS: hhxsv5/laravel-s#341

Based on https://wiki.swoole.com/#/http_server?id=setheader we try to use an array type for header values, but it emits an error under HTTP/2.

Test script (foo.php):

<?php

$http = new Swoole\Http\Server("127.0.0.1", 9501);
$http->set(['open_http2_protocol' => true]);

$http->on('request', function ($request, $response) {
    $response->header('Test-Value', [
        "a\r\n",
        'd5678',
        "e  \n ",
        null,
        5678,
        3.1415926,
    ]);

    $response->end("<h1>Hello Swoole. #".rand(1000, 9999)."</h1>");
});
$http->start();

2. What did you expect to see?

Multiple headers with no error, such as this:

$ curl -v http://localhost:9501
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 9501 (#0)
> GET / HTTP/1.1
> Host: localhost:9501
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< Test-Value: a
< Test-Value: d5678
< Test-Value: e
< Test-Value: 5678
< Test-Value: 3.1415926
< Server: swoole-http-server
< Connection: keep-alive
< Content-Type: text/html
< Date: Wed, 07 Apr 2021 06:55:36 GMT
< Content-Length: 28
<
* Connection #0 to host localhost left intact
<h1>Hello Swoole. #8020</h1>* Closing connection 0

3. What did you see instead?

A single header with value Array:

$ curl --http2-prior-knowledge -v http://localhost:9501
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 9501 (#0)
* Using HTTP2, server supports multi-use
* Connection state changed (HTTP/2 confirmed)
* Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0
* Using Stream ID: 1 (easy handle 0x7fdc0e80d600)
> GET / HTTP/2
> Host: localhost:9501
> User-Agent: curl/7.64.1
> Accept: */*
>
* Connection state changed (MAX_CONCURRENT_STREAMS == 128)!
< HTTP/2 200
< test-value: Array
< server: swoole-http-server
< date: Wed, 07 Apr 2021 06:55:43 GMT
< content-type: text/html
< content-length: 28
<
* Connection #0 to host localhost left intact
<h1>Hello Swoole. #1940</h1>* Closing connection 0

And an error logged in the PHP console:

PHP Notice:  Array to string conversion in $DIR/foo.php on line 16

Notice: Array to string conversion in $DIR/foo.php on line 16

4. What version of Swoole are you using (show your php --ri swoole)?

4.6.3 and 4.6.4

5. What is your machine environment used (show your uname -a & php -v & gcc -v) ?

Darwin C02CN25XMD6P 19.6.0 Darwin Kernel Version 19.6.0: Sun Jul 5 00:43:10 PDT 2020; root:xnu-6153.141.1~9/RELEASE_X86_64 x86_64

PHP 7.4.16 (cli) (built: Mar 4 2021 20:49:25) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
with Zend OPcache v7.4.16, Copyright (c), by Zend Technologies

Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include/c++/4.2.1
Apple clang version 12.0.0 (clang-1200.0.26.2)
Target: x86_64-apple-darwin19.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin

Problem also exhibits in a separate Debian-based container environment.

[matyhtf]

46ea525