[gtk: 1/2] gtkimmodule: make match_backend() query

[Matthias Clasen <matthiasc src gnome org>]

commit 86cd5c04bdd4aa2cfe4ecd4cce505d23e4d09d76
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Mon Mar 12 17:46:57 2018 -0400

    gtkimmodule: make match_backend() query
    
    …the wayland registry.
    
    Wnen _gtk_im_module_get_default_context_id calls
    match_backend (context_id) and the default GdkDisplay
    is wayland, match_backend() should return TRUE only if
    gdk_wayland_display_query_registry (display, "gtk_text_input_manager")
    returns TRUE.

 gtk/gtkimmodule.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkimmodule.c b/gtk/gtkimmodule.c
index 0c99553423..bdf956dd63 100644
--- a/gtk/gtkimmodule.c
+++ b/gtk/gtkimmodule.c
@@ -119,7 +119,13 @@ match_backend (const char *context_id)
 {
 #ifdef GDK_WINDOWING_WAYLAND
   if (g_strcmp0 (context_id, "wayland") == 0)
-    return GDK_IS_WAYLAND_DISPLAY (gdk_display_get_default ());
+    {
+      GdkDisplay *display = gdk_display_get_default ();
+
+      return GDK_IS_WAYLAND_DISPLAY (display) &&
+             gdk_wayland_display_query_registry (display,
+                                                 "gtk_text_input_manager");
+    }
 #endif
 
 #ifdef GDK_WINDOWING_BROADWAY