[gimp] libgimp: _gimp_gp_param_to_value() must ref object array elements

[Michael Natterer <mitch src gnome org>]

commit 3dc354e848f744c093442d736cd9562983100a80
Author: Michael Natterer <mitch gimp org>
Date:   Thu Sep 5 14:40:05 2019 +0200

    libgimp: _gimp_gp_param_to_value() must ref object array elements
    
    because the subsequent gimp_value_array_unref() unrefs them
    again.

 libgimp/gimpgpparams-body.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/libgimp/gimpgpparams-body.c b/libgimp/gimpgpparams-body.c
index 7e2b9bcb4b..924e342f92 100644
--- a/libgimp/gimpgpparams-body.c
+++ b/libgimp/gimpgpparams-body.c
@@ -601,6 +601,9 @@ _gimp_gp_param_to_value (gpointer        gimp,
             {
               objects[i] = (GObject *) get_display_by_id (gimp, id);
             }
+
+          if (objects[i])
+            g_object_ref (objects[i]);
         }
 
       gimp_value_take_object_array (value, object_type, objects,