[gtk+] Avoid a crash in gtk_im_context_ime_reset

[Matthias Clasen <matthiasc src gnome org>]

commit 74f57ee04dfd06d4082443dee20cd8a16428d3d9
Author: Kazuki Iwamoto <iwm maid org>
Date:   Mon Jun 6 19:33:23 2011 -0400

    Avoid a crash in gtk_im_context_ime_reset
    
    When GTK+ runs with inputim-ime.dll module, there is NULL
    pointer reference. Because "context_ime->client_window" may
    be NULL in gtk_im_context_ime_reset.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=644906

 modules/input/gtkimcontextime.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/modules/input/gtkimcontextime.c b/modules/input/gtkimcontextime.c
index 786fb9d..16f2e7d 100644
--- a/modules/input/gtkimcontextime.c
+++ b/modules/input/gtkimcontextime.c
@@ -348,6 +348,9 @@ gtk_im_context_ime_reset (GtkIMContext *context)
   HWND hwnd;
   HIMC himc;
 
+  if (!context_ime->client_window)
+    return;
+
   hwnd = GDK_WINDOW_HWND (context_ime->client_window);
   himc = ImmGetContext (hwnd);
   if (!himc)