[gnome-shell] st: initialize static variables to NULL

[Cosimo Cecchi <cosimoc src gnome org>]

commit d5cac6559d1759ca717f8c0ca9cabbc3d19cd456
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Tue Jun 6 14:27:00 2017 -0700

    st: initialize static variables to NULL
    
    https://bugzilla.gnome.org/show_bug.cgi?id=783484

 src/st/st-entry.c   |    4 ++--
 src/st/st-im-text.c |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/st/st-entry.c b/src/st/st-entry.c
index 7ccf6bd..152f3eb 100644
--- a/src/st/st-entry.c
+++ b/src/st/st-entry.c
@@ -718,8 +718,8 @@ st_entry_key_focus_in (ClutterActor *actor)
   clutter_actor_grab_key_focus (priv->entry);
 }
 
-static StEntryCursorFunc cursor_func;
-static gpointer          cursor_func_data;
+static StEntryCursorFunc cursor_func = NULL;
+static gpointer          cursor_func_data = NULL;
 
 /**
  * st_entry_set_cursor_func: (skip)
diff --git a/src/st/st-im-text.c b/src/st/st-im-text.c
index 5f86f88..6498cfb 100644
--- a/src/st/st-im-text.c
+++ b/src/st/st-im-text.c
@@ -202,7 +202,7 @@ st_im_text_get_paint_volume (ClutterActor       *self,
   return clutter_paint_volume_set_from_allocation (volume, self);
 }
 
-static GdkWindow *event_window;
+static GdkWindow *event_window = NULL;
 
 void
 st_im_text_set_event_window (GdkWindow *window)