instanceof fails if checked against a variable

[schinkel-zz]

Consider the following code:

{$interface = 'a_random_interface'}
{$object = 'a string'}
{if $object instanceof $interface}
    <p>All good</p>
{else}
    <p>Something's wrong</p>
{/if}

This worked like a charm up until Smarty 3.1.23, but fails in Smarty 3.1.24 and upwards with the following error message:

PHP Fatal error:  Uncaught  --> Smarty Compiler: Syntax error in template "/var/www/examples/templates/correct.tpl"  on line 3 "{if $object instanceof $interface}"  - Unexpected "$interface", expected one of: "id, name" , NAMESPACE <-- 
  thrown in /var/www/examples/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatecompilerbase.php on line 3

I am using the following code to render this template:

$smarty = new \Smarty();
$smarty
    ->setCompileDir(sys_get_temp_dir())
    ->setCacheDir(sys_get_temp_dir())
    ->setPluginsDir(SMARTY_PLUGINS_DIR)
    ->disableSecurity();
$smarty->display(__DIR__ . '/templates/correct.tpl');

The following snippet does compile and produces the expected "Something's wrong":

{$interface = 'a_random_interface'}
{$object = $smarty}
{if $object instanceof aaa}
    <p>All good</p>
{else}
    <p>Something's wrong</p>
{/if}

[Henkiebob]

+1

[uwetews]

I can confirm this bug. The fix will go into the master branch and version 3.1.28 in a few days.

Possible fix:

in lexer/smarty_internal_templateparser.y

expr(res)        ::= variable(v1) INSTANCEOF(i) ns1(v2). {
      res = v1.i.v2;
}

expr(res)        ::= variable(v1) INSTANCEOF(i) variable(v2). {
      res = v1.i.v2;
}

add the second expression.

Get with composer "smarty/smarty-lexer": "~3.1@dev"
Run Create_Template_Parser.php

Because of other changes under work I can't commit it directly immediately

.

[uwetews]

The fix is now available in the master branch and will be included in the upcoming 3.1.28

[schinkel-zz]

Cool, thanks!