[gimp] app: ref the symmetry in gimp_image_symmetry_add()

[Michael Natterer <mitch src gnome org>]

commit 8b7939d226e969befd4be7ad9c03d5b685850810
Author: Michael Natterer <mitch gimp org>
Date:   Thu Feb 4 20:58:00 2016 +0100

    app: ref the symmetry in gimp_image_symmetry_add()
    
    so we have proper ref/unref symmetry in symmetry_add/remove().

 app/core/gimpimage-symmetry.c |    5 ++---
 app/core/gimpimage.c          |    2 ++
 2 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/app/core/gimpimage-symmetry.c b/app/core/gimpimage-symmetry.c
index 356f72c..93d8ca5 100644
--- a/app/core/gimpimage-symmetry.c
+++ b/app/core/gimpimage-symmetry.c
@@ -98,7 +98,7 @@ gimp_image_symmetry_add (GimpImage    *image,
   private = GIMP_IMAGE_GET_PRIVATE (image);
 
   private->symmetries = g_list_prepend (private->symmetries,
-                                        sym);
+                                        g_object_ref (sym));
 }
 
 /**
@@ -123,8 +123,7 @@ gimp_image_symmetry_remove (GimpImage    *image,
   if (private->active_symmetry == sym)
     gimp_image_set_active_symmetry (image, G_TYPE_NONE);
 
-  private->symmetries = g_list_remove (private->symmetries,
-                                       sym);
+  private->symmetries = g_list_remove (private->symmetries, sym);
   g_object_unref (sym);
 }
 
diff --git a/app/core/gimpimage.c b/app/core/gimpimage.c
index bb3e937..02ba6be 100644
--- a/app/core/gimpimage.c
+++ b/app/core/gimpimage.c
@@ -898,6 +898,8 @@ gimp_image_set_property (GObject      *object,
             GimpSymmetry *sym = gimp_image_symmetry_new (image, type);
 
             gimp_image_symmetry_add (image, sym);
+            g_object_unref (sym);
+
             private->active_symmetry = sym;
           }