Merge pull request #217 from clue-labs/php7.3-excludes-tls1.3

Improve test suite to exclude TLS 1.3 tests on PHP 7.3

Author: jsor

tests/FunctionalSecureServerTest.php

@@ -50,8 +50,11 @@ public function testClientCanConnectToServer()
 
     public function testClientUsesTls13ByDefaultWhenSupportedByOpenSSL()
     {
-        if (PHP_VERSION_ID < 70000 || !$this->supportsTls13()) {
-            $this->markTestSkipped('Test requires PHP 7+ for crypto meta data and OpenSSL 1.1.1+ for TLS 1.3');
+        if (PHP_VERSION_ID < 70000 || (PHP_VERSION_ID >= 70300 && PHP_VERSION_ID < 70400) || !$this->supportsTls13()) {
+            // @link https://github.com/php/php-src/pull/3909 explicitly adds TLS 1.3 on PHP 7.4
+            // @link https://github.com/php/php-src/pull/3317 implicitly limits to TLS 1.2 on PHP 7.3
+            // all older PHP versions support TLS 1.3 (provided OpenSSL supports it), but only PHP 7 allows checking the version
+            $this->markTestSkipped('Test requires PHP 7+ for crypto meta data (but excludes PHP 7.3 because it implicitly limits to TLS 1.2) and OpenSSL 1.1.1+ for TLS 1.3');
         }
 
         $loop = Factory::create();