[gimp] libgimpwidgets: make GimpDialog's help_id settable after construction

[Michael Natterer <mitch src gnome org>]

commit a94030052521e481cfe996044947c13b4e5c0276
Author: Michael Natterer <mitch gimp org>
Date:   Sun Jan 17 17:35:33 2016 +0100

    libgimpwidgets: make GimpDialog's help_id settable after construction

 libgimpwidgets/gimpdialog.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/libgimpwidgets/gimpdialog.c b/libgimpwidgets/gimpdialog.c
index 32b13e2..7255ee4 100644
--- a/libgimpwidgets/gimpdialog.c
+++ b/libgimpwidgets/gimpdialog.c
@@ -129,8 +129,7 @@ gimp_dialog_class_init (GimpDialogClass *klass)
   g_object_class_install_property (object_class, PROP_HELP_ID,
                                    g_param_spec_string ("help-id", NULL, NULL,
                                                         NULL,
-                                                        GIMP_PARAM_READWRITE |
-                                                        G_PARAM_CONSTRUCT_ONLY));
+                                                        GIMP_PARAM_READWRITE));
 
   /**
    * GimpDialog:parent:
@@ -234,7 +233,9 @@ gimp_dialog_set_property (GObject      *object,
       break;
 
     case PROP_HELP_ID:
+      g_free (private->help_id);
       private->help_id = g_value_dup_string (value);
+      gimp_help_set_help_data (GTK_WIDGET (object), NULL, private->help_id);
       break;
 
     case PROP_PARENT: