[libdazzle] signal-group: be more flexible to re-entrancy

[Christian Hergert <chergert src gnome org>]

commit 3f05020089023c243973067a1cc28a2ef1386ff6
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jan 12 14:27:40 2018 -0800

    signal-group: be more flexible to re-entrancy

 src/bindings/dzl-signal-group.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/src/bindings/dzl-signal-group.c b/src/bindings/dzl-signal-group.c
index d75f702..1beea8f 100644
--- a/src/bindings/dzl-signal-group.c
+++ b/src/bindings/dzl-signal-group.c
@@ -182,7 +182,10 @@ dzl_signal_group_bind_handler (DzlSignalGroup *self,
   g_assert (handler != NULL);
   g_assert (handler->signal_id != 0);
   g_assert (handler->closure != NULL);
-  g_assert (handler->handler_id == 0);
+
+  /* Possibly a re-entrancy issue */
+  if (handler->handler_id != 0)
+    return;
 
   handler->handler_id = g_signal_connect_closure_by_id (self->target,
                                                         handler->signal_id,