[gegl] gegl: fix the memory management of gegl_chant_curve()

[Michael Natterer <mitch src gnome org>]

commit 3133c01b47c29472acd8b5a8de0793091757e868
Author: Michael Natterer <mitch gimp org>
Date:   Mon Jun 3 00:38:43 2013 +0200

    gegl: fix the memory management of gegl_chant_curve()
    
    Make it ref the passed default_curve, and create a new one for each
    chanted property. Changed gegl_curve_default_curve() to
    gegl_curve_new_default() and always return a newly allocated one. Add
    gegl_curve_duplicate() because we can't use the default curve in
    GeglParamCurve::value_set_default().

 gegl/gegl-chant.h                |    6 +++-
 gegl/property-types/gegl-curve.c |   44 ++++++++++++++++++++++++++++---------
 gegl/property-types/gegl-curve.h |   22 +++++++++++++++++-
 3 files changed, 57 insertions(+), 15 deletions(-)
---
diff --git a/gegl/gegl-chant.h b/gegl/gegl-chant.h
index b2bafa0..09c2703 100644
--- a/gegl/gegl-chant.h
+++ b/gegl/gegl-chant.h
@@ -970,13 +970,15 @@ gegl_chant_class_intern_init (gpointer klass)
                                                           G_PARAM_CONSTRUCT |\
                                                           GEGL_PARAM_PAD_INPUT)));
 #define gegl_chant_curve(name, nick, blurb)                                  \
+  { GeglCurve *_gegl_chant_default_curve = gegl_curve_new_default ();        \
   g_object_class_install_property (object_class, PROP_##name,                \
                                    gegl_param_spec_curve (#name, nick, blurb,\
-                                                          gegl_curve_default_curve(),\
+                                                          _gegl_chant_default_curve,\
                                                           (GParamFlags) (    \
                                                           G_PARAM_READWRITE |\
                                                           G_PARAM_CONSTRUCT |\
-                                                          GEGL_PARAM_PAD_INPUT)));
+                                                          GEGL_PARAM_PAD_INPUT)));\
+  g_object_unref (_gegl_chant_default_curve); }
 
 #include GEGL_CHANT_C_FILE
 
diff --git a/gegl/property-types/gegl-curve.c b/gegl/property-types/gegl-curve.c
index 68a4b57..2e42155 100644
--- a/gegl/property-types/gegl-curve.c
+++ b/gegl/property-types/gegl-curve.c
@@ -146,26 +146,48 @@ gegl_curve_new (gdouble y_min,
   GeglCurve        *self = GEGL_CURVE (g_object_new (GEGL_TYPE_CURVE, NULL));
   GeglCurvePrivate *priv = GEGL_CURVE_GET_PRIVATE (self);
 
-  gegl_curve_init (self);
   priv->y_min = y_min;
   priv->y_max = y_max;
 
   return self;
 }
 
-GeglCurve*
-gegl_curve_default_curve (void)
+GeglCurve *
+gegl_curve_new_default (void)
+{
+  GeglCurve *curve = gegl_curve_new (0.0, 1.0);
+
+  gegl_curve_add_point (curve, 0.0, 0.0);
+  gegl_curve_add_point (curve, 1.0, 1.0);
+
+  return curve;
+}
+
+GeglCurve *
+gegl_curve_duplicate (GeglCurve *curve)
 {
-  static GeglCurve *curve = NULL;
+  GeglCurve *new;
+  gdouble    min_y, max_y;
+  gint       n_points;
+  gint       i;
+
+  g_return_val_if_fail (GEGL_IS_CURVE (curve), NULL);
+
+  gegl_curve_get_y_bounds (curve, &min_y, &max_y);
+
+  new = gegl_curve_new (min_y, max_y);
 
-  if (curve == NULL)
+  n_points = gegl_curve_num_points (curve);
+
+  for (i = 0; i < n_points; i++)
     {
-      curve = gegl_curve_new (0.0, 1.0);
-      gegl_curve_add_point (curve, 0.0, 0.0);
-      gegl_curve_add_point (curve, 1.0, 1.0);
+      gdouble x, y;
+
+      gegl_curve_get_point (curve, i, &x, &y);
+      gegl_curve_add_point (new, x, y);
     }
 
-  return curve;
+  return new;
 }
 
 void
@@ -465,7 +487,7 @@ value_set_default (GParamSpec *param_spec,
 {
   GeglParamCurve *gegl_curve = GEGL_PARAM_CURVE (param_spec);
 
-  g_value_set_object (value, gegl_curve->default_curve);
+  g_value_take_object (value, gegl_curve_duplicate (gegl_curve->default_curve));
 }
 
 GType
@@ -506,7 +528,7 @@ gegl_param_spec_curve (const gchar *name,
   param_curve = g_param_spec_internal (GEGL_TYPE_PARAM_CURVE,
                                        name, nick, blurb, flags);
 
-  param_curve->default_curve = default_curve;
+  param_curve->default_curve = g_object_ref (default_curve);
 
   return G_PARAM_SPEC (param_curve);
 }
diff --git a/gegl/property-types/gegl-curve.h b/gegl/property-types/gegl-curve.h
index c1eb59f..8e6f602 100644
--- a/gegl/property-types/gegl-curve.h
+++ b/gegl/property-types/gegl-curve.h
@@ -65,6 +65,26 @@ GType        gegl_curve_get_type       (void) G_GNUC_CONST;
 GeglCurve  * gegl_curve_new            (gdouble      y_min,
                                         gdouble      y_max);
 
+/**
+ * gegl_curve_new_default:
+ *
+ * Create a default #GeglCurve with an identify mapping of
+ * (0.0..1.0) -> (0.0..1.0).
+ *
+ * Returns the newly created default #GeglCurve.
+ */
+GeglCurve  * gegl_curve_new_default    (void);
+
+/**
+ * gegl_curve_duplicate:
+ * @curve: the curve to duplicate.
+ *
+ * Create a copy of @curve.
+ *
+ * Returns the copied #GeglCurve.
+ */
+GeglCurve  * gegl_curve_duplicate      (GeglCurve   *curve);
+
 
 /**
  * gegl_curve_get_y_bounds:
@@ -165,8 +185,6 @@ void         gegl_curve_calc_values    (GeglCurve   *curve,
 #define GEGL_TYPE_PARAM_CURVE           (gegl_param_curve_get_type ())
 #define GEGL_IS_PARAM_SPEC_CURVE(pspec) (G_TYPE_CHECK_INSTANCE_TYPE ((pspec), GEGL_TYPE_PARAM_CURVE))
 
-GeglCurve  * gegl_curve_default_curve  (void) G_GNUC_CONST;
-
 GType        gegl_param_curve_get_type (void) G_GNUC_CONST;
 
 GParamSpec * gegl_param_spec_curve     (const gchar *name,