[gnome-shell] StEntry: fix crash when hint actor is NULL

[Marc-Antoine Perennou <marcop src gnome org>]

commit 5ec0ad4e9cf8a88e3a715fdef4bf1f227b274d2d
Author: Marc-Antoine Perennou <Marc-Antoine Perennou com>
Date:   Tue Sep 12 12:23:46 2017 +0200

    StEntry: fix crash when hint actor is NULL
    
    https://bugzilla.gnome.org/show_bug.cgi?id=787580
    
    Signed-off-by: Marc-Antoine Perennou <Marc-Antoine Perennou com>

 src/st/st-entry.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/st/st-entry.c b/src/st/st-entry.c
index fc9ffbf..18e6a25 100644
--- a/src/st/st-entry.c
+++ b/src/st/st-entry.c
@@ -1106,7 +1106,7 @@ st_entry_get_text (StEntry *entry)
   g_return_val_if_fail (ST_IS_ENTRY (entry), NULL);
 
   priv = st_entry_get_instance_private (entry);
-  if (clutter_actor_is_visible (priv->hint_actor))
+  if (priv->hint_actor != NULL && clutter_actor_is_visible (priv->hint_actor))
     return "";
   else
     return clutter_text_get_text (CLUTTER_TEXT (priv->entry));