Fix crash in signal emission optimization

The trace of the signal emission of the was calculating the instance
type after the instance was unrefed. Fix this by keeping the instance type around.

diff --git a/gobject/gsignal.c b/gobject/gsignal.c
index a45b334..8e067c3 100644 (file)
--- a/gobject/gsignal.c
+++ b/gobject/gsignal.c
@@ -3168,6 +3168,7 @@ g_signal_emit_valist (gpointer instance,
          Emission emission;
          GValue *return_accu, accu = G_VALUE_INIT;
          guint signal_id;
+         GType instance_type = G_TYPE_FROM_INSTANCE (instance);
          GValue emission_return = G_VALUE_INIT;
           GType rtype = node->return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE;
          gboolean static_scope = node->return_type & G_SIGNAL_TYPE_STATIC_SCOPE;
@@ -3186,12 +3187,12 @@ g_signal_emit_valist (gpointer instance,
          emission.ihint.detail = detail;
          emission.ihint.run_type = run_type;
          emission.state = EMISSION_RUN;
-         emission.chain_type = G_TYPE_FROM_INSTANCE (instance);
+         emission.chain_type = instance_type;
          emission_push (&g_recursive_emissions, &emission);
 
          SIGNAL_UNLOCK ();
 
-         TRACE(GOBJECT_SIGNAL_EMIT(signal_id, detail, instance, G_TYPE_FROM_INSTANCE (instance)));
+         TRACE(GOBJECT_SIGNAL_EMIT(signal_id, detail, instance, instance_type));
 
          if (rtype != G_TYPE_NONE)
            g_value_init (&emission_return, rtype);
@@ -3247,7 +3248,7 @@ g_signal_emit_valist (gpointer instance,
                }
            }
          
-         TRACE(GOBJECT_SIGNAL_EMIT_END(signal_id, detail, instance, G_TYPE_FROM_INSTANCE (instance)));
+         TRACE(GOBJECT_SIGNAL_EMIT_END(signal_id, detail, instance, instance_type));
 
          return;
        }