Add failing test for bug#73297

ext/standard/tests/http/bug73297.phpt

@@ -0,0 +1,41 @@
+--TEST--
+Bug #73297 (Ignore 100 Continue returned by HTTP/1.1 servers)
+--INI--
+allow_url_fopen=1
+--SKIPIF--
+<?php require 'server.inc'; http_server_skipif('tcp://127.0.0.1:12342'); ?>
+--FILE--
+<?php
+require 'server.inc';
+
+$ctx = stream_context_create();
+
+function do_test() {
+  $options = [
+    'http' => [
+      'protocol_version' => '1.1',
+      'header' => 'Connection: Close'
+    ],
+  ];
+
+  $ctx = stream_context_create($options);
+
+  $responses = [
+    "data://text/plain,HTTP/1.1 100 Continue\r\n\r\nHTTP/1.1 200 OK\r\n\r\n"
+      . "Hello"
+  ];
+  $pid = http_server('tcp://127.0.0.1:12342', $responses);
+
+  echo file_get_contents('http://127.0.0.1:12342/', false, $ctx);
+  echo "\n";
+
+  http_server_kill($pid);
+}
+
+do_test();
+echo "\n";
+
+?>
+--EXPECT--
+Hello
+