The target_language specified via i18n:target in a macro is not passed to the filled slot. #439
Description
I have this template that defines a macro with a slot:
<html metal:define-macro="main" i18n:target="string:fr">
<head>
<title i18n:translate="">Hello world!</title>
</head>
<body>
<metal:content define-slot="content">
<h1 i18n:translate="">Hello world!</h1>
</metal:content>
</body>
</html>This second template that uses that macro and customizes the slot:
<html metal:use-macro="load('332-master-i18n-target.pt').macros['main']">
<metal:slot fill-slot="content">
<h1 i18n:translate="">Hello world!</h1>
<p>Ciao!</p>
</metal:slot>
</html>I expect the output to be like:
<html>
<head>
<title>Hello world! ('Hello world!' translation into 'fr')</title>
</head>
<body>
<h1>Hello world! ('Hello world!' translation into 'fr')</h1>
<p>Ciao!</p>
</body>
</html>Instead it is like:
<html>
<head>
<title>Hello world! ('Hello world!' translation into 'fr')</title>
</head>
<body>
<h1>Hello world! ('Hello world!' translation into 'use')</h1>
<p>Ciao!</p>
</body>
</html>As you can see <title> is translated, but the <h1> is not.
It seems like the translation target is not passed to the second template.
Is this the expected behavior?
Note that until version 4.2.0 this was working as I was expecting.