Tests to ensure BC with undocumented behavior used in hacks

Should become obsolete, once behaviors change.

ext/mysqli/tests/mysqli_open_bug74432.phpt

@@ -0,0 +1,29 @@
+--TEST--
+Bug #74432, BC issue on undocumented connect string
+--SKIPIF--
+<?php
+require_once('skipif.inc');
+require_once('skipifemb.inc');
+require_once('skipifconnectfailure.inc');
+?>
+--FILE--
+<?php
+	/* This behavior is undocumented, but might be in use. Until there's no officially
+		supported alternative, ensure changes doesn't cause BC breach. Otherwise,
+		the test should be removed once the undocumented behavior changes. */
+
+	require_once("connect.inc");
+
+	$handle = mysqli_connect("$host:$port", $user, $passwd);
+
+	var_dump($handle);
+
+	if ($handle) {
+		mysqli_close($handle);
+	}
+?>
+--EXPECTF--
+object(mysqli)#%d (%d) {
+%A
+}
+