module_gettext: translate a string in the text domain of a module

This is needed for out-of-tree modules. We need to translate their
plugin descriptor strings from their domain.

include/vlc_modules.h

@@ -52,6 +52,7 @@ VLC_EXPORT( const char *, module_get_name, ( const module_t *m, bool long_name )
 VLC_EXPORT( const char *, module_get_help, ( const module_t *m ) );
 VLC_EXPORT( const char *, module_get_capability, ( const module_t *m ) );
 VLC_EXPORT( int, module_get_score, ( const module_t *m ) );
+VLC_EXPORT( const char *, module_gettext, ( const module_t *, const char * ) );
 
 static inline module_t *module_get_main (void)
 {

src/libvlccore.sym

@@ -237,6 +237,7 @@ module_get_help
 module_get_name
 module_get_object
 module_get_score
+module_gettext
 module_hold
 module_list_free
 module_list_get

src/modules/modules.c

@@ -49,6 +49,9 @@
 #ifdef HAVE_UNISTD_H
 #   include <unistd.h>
 #endif
+#ifdef ENABLE_NLS
+# include <libintl.h>
+#endif
 
 #include "config/configuration.h"
 
@@ -293,6 +296,24 @@ int module_get_score( const module_t *m )
     return m->i_score;
 }
 
+/**
+ * Translate a string using the module's text domain
+ *
+ * \param m the module
+ * \param str the American English ASCII string to localize
+ * \return the gettext-translated string
+ */
+const char *module_gettext (const module_t *m, const char *str)
+{
+#ifdef ENABLE_NLS
+    const char *domain = m->domain ? m->domain : PACKAGE_NAME;
+    return dgettext (domain, str);
+#else
+    (void)m;
+    return str;
+#endif
+}
+
 module_t *module_hold (module_t *m)
 {
     vlc_hold (&m->vlc_gc_data);