[PATCH] Use gettext as fallback for translations

[Ludwig Nussel]

Upstream polkit action files do not necessarily contain translations for
all languages a distribution supports. And even if all translations are
contained in the head branch, distributions sometimes need to ship older
versions of packages. In order to allow retrofitting translations and
shipping language packs for polkit actions without having to patch and
rebuild packages gettext could be used as fallback. That way only
additional .mo files have to be installed.
So this patch makes polkit call into gettext with the domain
'polkit-action-distro-translations' if an xml doesn't contain
translations for the requested language.
---
 src/polkitbackend/polkitbackendactionpool.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/polkitbackend/polkitbackendactionpool.c b/src/polkitbackend/polkitbackendactionpool.c
index 3894fe9..9252788 100644
--- a/src/polkitbackend/polkitbackendactionpool.c
+++ b/src/polkitbackend/polkitbackendactionpool.c
@@ -24,6 +24,7 @@
 #include <pwd.h>
 #include <string.h>
 #include <expat.h>
+#include <locale.h>
 
 #include <polkit/polkit.h>
 #include <polkit/polkitprivate.h>
@@ -1132,8 +1133,20 @@ _localize (GHashTable *translations,
   if (result != NULL)
     goto out;
 
-  /* fall back to untranslated */
-  result = untranslated;
+  /* try distro provided language bundle via gettext */
+
+  /* Set LANG and locale so g_dgettext() + friends work below */
+  if (setlocale (LC_ALL, lang) == NULL)
+    {
+      g_printerr ("Invalid locale '%s'\n", lang);
+    }
+  g_setenv ("LANG", lang, TRUE);
+
+  result = g_dgettext ("polkit-action-distro-translations", untranslated);
+
+  /* Back to C! */
+  setlocale (LC_ALL, "C");
+  g_setenv ("LANG", "C", TRUE);
 
 out:
   return result;
-- 
2.12.2