[evolution] Bug 708319 - Workaround crash under e_mail_shell_view_update_popup_labels()

[Milan Crha <mcrha src gnome org>]

commit 89ae10cd675b2f17122dc4c4e5c06f818d7097ca
Author: Milan Crha <mcrha redhat com>
Date:   Thu Aug 27 19:12:46 2015 +0200

    Bug 708319 - Workaround crash under e_mail_shell_view_update_popup_labels()

 modules/mail/e-mail-shell-view-actions.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/modules/mail/e-mail-shell-view-actions.c b/modules/mail/e-mail-shell-view-actions.c
index faa2bc2..08c0749 100644
--- a/modules/mail/e-mail-shell-view-actions.c
+++ b/modules/mail/e-mail-shell-view-actions.c
@@ -2428,6 +2428,9 @@ e_mail_shell_view_update_popup_labels (EMailShellView *mail_shell_view)
        shell_backend = e_shell_view_get_shell_backend (shell_view);
        ui_manager = e_shell_window_get_ui_manager (shell_window);
 
+       g_return_if_fail (ui_manager != NULL);
+       g_return_if_fail (GTK_IS_UI_MANAGER (ui_manager));
+
        backend = E_MAIL_BACKEND (shell_backend);
        session = e_mail_backend_get_session (backend);
        label_store = e_mail_ui_session_get_label_store (