Add tests for json_last_error()/json_last_error_msg() failures

ext/json/tests/json_last_error_error.phpt

@@ -0,0 +1,22 @@
+--TEST--
+json_last_error() failures
+--SKIPIF--
+<?php !extension_loaded('json') && die('skip json extension not available') ?>
+--FILE--
+<?php
+
+var_dump(json_last_error());
+var_dump(json_last_error(TRUE));
+var_dump(json_last_error('some', 4, 'args', 'here'));
+
+
+?>
+--EXPECTF--
+int(0)
+
+Warning: json_last_error() expects exactly 0 parameters, 1 given in %s on line %d
+NULL
+
+Warning: json_last_error() expects exactly 0 parameters, 4 given in %s on line %d
+NULL
+

ext/json/tests/json_last_error_msg_error.phpt

@@ -0,0 +1,21 @@
+--TEST--
+json_last_error_msg() failures
+--SKIPIF--
+<?php !extension_loaded('json') && die('skip json extension not available') ?>
+--FILE--
+<?php
+
+var_dump(json_last_error_msg());
+var_dump(json_last_error_msg(TRUE));
+var_dump(json_last_error_msg('some', 4, 'args', 'here'));
+
+?>
+--EXPECTF--
+string(8) "No error"
+
+Warning: json_last_error_msg() expects exactly 0 parameters, 1 given in %s on line %d
+NULL
+
+Warning: json_last_error_msg() expects exactly 0 parameters, 4 given in %s on line %d
+NULL
+