common: Add flatpak_context_load_for_app helper

This looks for an installed app, using the current
one, and loads its permissions and overriders
(ignoring the ones from the runtime).

This is useful if you want to know the permissions
for an application by name, such as in the
document portal.

common/flatpak-run.c

@@ -4520,6 +4520,35 @@ add_rest_args (const char  *app_id,
   return TRUE;
 }
 
+FlatpakContext *
+flatpak_context_load_for_app (const char     *app_id,
+                              GError        **error)
+{
+  g_autofree char *app_ref = NULL;
+  g_autoptr(FlatpakContext) app_context = NULL;
+  g_autoptr(FlatpakDeploy) app_deploy = NULL;
+  g_autoptr(FlatpakContext) overrides = NULL;
+  g_autoptr(GKeyFile) metakey = NULL;
+
+  app_ref = flatpak_find_current_ref (app_id, NULL, error);
+  if (app_ref == NULL)
+    return NULL;
+
+  app_deploy = flatpak_find_deploy_for_ref (app_ref, NULL, error);
+  if (app_deploy == NULL)
+    return NULL;
+
+  metakey = flatpak_deploy_get_metadata (app_deploy);
+  app_context = flatpak_app_compute_permissions (metakey, NULL, error);
+  if (app_context == NULL)
+    return NULL;
+
+  overrides = flatpak_deploy_get_overrides (app_deploy);
+  flatpak_context_merge (app_context, overrides);
+
+  return g_steal_pointer (&app_context);
+}
+
 gboolean
 flatpak_run_app (const char     *app_ref,
                  FlatpakDeploy  *app_deploy,

common/flatpak-run.h

@@ -71,6 +71,8 @@ void           flatpak_context_to_args (FlatpakContext *context,
 gboolean       flatpak_context_get_needs_session_bus_proxy (FlatpakContext *context);
 gboolean       flatpak_context_get_needs_system_bus_proxy (FlatpakContext *context);
 
+FlatpakContext *flatpak_context_load_for_app (const char     *app_id,
+                                              GError        **error);
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (FlatpakContext, flatpak_context_free)