[gtk+/gtk-2-24] gtkimcontexttime.c: Check context_ime->client_window is not NULL

[Michael Natterer <mitch src gnome org>]

commit 2d57ddd6ef0ef44382be7080484e2408375eb463
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Wed Aug 29 14:03:46 2012 +0800

    gtkimcontexttime.c: Check context_ime->client_window is not NULL
    
    Be a bit more careful in get_pango_attr_list() and
    get_utf8_preedit_string() to ensure that the client_window is properly
    created before proceeding, to avoid access violation/segfault crashes on
    Windows with IME installed, especially when running the pickers demo.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=682919
    (cherry picked from commit a866ed737810ea32ec55260ad512f386a4e6df5d)

 modules/input/gtkimcontextime.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/modules/input/gtkimcontextime.c b/modules/input/gtkimcontextime.c
index b15f0f2..4682146 100644
--- a/modules/input/gtkimcontextime.c
+++ b/modules/input/gtkimcontextime.c
@@ -376,6 +376,9 @@ get_utf8_preedit_string (GtkIMContextIME *context_ime, gint *pos_ret)
   if (pos_ret)
     *pos_ret = 0;
 
+  if (!context_ime->client_window)
+    return g_strdup ("");
+
   hwnd = gdk_win32_window_get_impl_hwnd (context_ime->client_window);
   himc = ImmGetContext (hwnd);
   if (!himc)
@@ -435,6 +438,9 @@ get_pango_attr_list (GtkIMContextIME *context_ime, const gchar *utf8str)
   HWND hwnd;
   HIMC himc;
 
+  if (!context_ime->client_window)
+    return attrs;
+
   hwnd = gdk_win32_window_get_impl_hwnd (context_ime->client_window);
   himc = ImmGetContext (hwnd);
   if (!himc)