[gnome-shell] gtk-embed: ensure we only listen for window-created events once

[Ray Strode <halfline src gnome org>]

commit 90c55e1977fde252b79bcfd9d0ef41144fb21fe2
Author: Ray Strode <rstrode redhat com>
Date:   Thu Sep 14 14:46:13 2017 -0400

    gtk-embed: ensure we only listen for window-created events once
    
    If a tray icon gets a mapped and unmapped and the mapped again
    in quick succession, we can end up with multiple handlers
    listening for window creation events.
    
    This commit tries to guard against that by only listening for
    window-created events when we don't  know the actor associated
    with the icon.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=787361

 src/shell-gtk-embed.c |   15 ++++++++-------
 1 files changed, 8 insertions(+), 7 deletions(-)
---
diff --git a/src/shell-gtk-embed.c b/src/shell-gtk-embed.c
index 176b413..5406104 100644
--- a/src/shell-gtk-embed.c
+++ b/src/shell-gtk-embed.c
@@ -124,13 +124,14 @@ shell_gtk_embed_on_window_mapped (GtkWidget     *object,
   ShellGtkEmbedPrivate *priv = shell_gtk_embed_get_instance_private (embed);
   MetaDisplay *display = shell_global_get_display (shell_global_get ());
 
-  /* Listen for new windows so we can detect when Mutter has
-     created a MutterWindow for this window */
-  priv->window_created_handler =
-    g_signal_connect (display,
-                      "window-created",
-                      G_CALLBACK (shell_gtk_embed_window_created_cb),
-                      embed);
+  if (priv->window_created_handler == 0 && priv->window_actor == NULL)
+    /* Listen for new windows so we can detect when Mutter has
+       created a MutterWindow for this window */
+    priv->window_created_handler =
+      g_signal_connect (display,
+                        "window-created",
+                        G_CALLBACK (shell_gtk_embed_window_created_cb),
+                        embed);
 }
 
 static void