[gegl] GeglNode: gegl_node_get_producer should take a const gchar *pad_name

[Debarshi Ray <debarshir src gnome org>]

commit 6ec74488beafda0c656b08df05979f0e5878aa24
Author: Debarshi Ray <debarshir gnome org>
Date:   Tue May 26 19:40:05 2015 +0200

    GeglNode: gegl_node_get_producer should take a const gchar *pad_name
    
    https://bugzilla.gnome.org/show_bug.cgi?id=749920

 gegl/graph/gegl-node.c |    6 +++---
 gegl/graph/gegl-node.h |    2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/gegl/graph/gegl-node.c b/gegl/graph/gegl-node.c
index a8acca6..3d9cfd2 100644
--- a/gegl/graph/gegl-node.c
+++ b/gegl/graph/gegl-node.c
@@ -1610,9 +1610,9 @@ gegl_node_get_debug_name (GeglNode *node)
 }
 
 GeglNode *
-gegl_node_get_producer (GeglNode *node,
-                        gchar    *pad_name,
-                        gchar   **output_pad_name)
+gegl_node_get_producer (GeglNode     *node,
+                        const gchar  *pad_name,
+                        gchar       **output_pad_name)
 {
   GeglNode *ret;
   gpointer pad;
diff --git a/gegl/graph/gegl-node.h b/gegl/graph/gegl-node.h
index df76656..ccea88e 100644
--- a/gegl/graph/gegl-node.h
+++ b/gegl/graph/gegl-node.h
@@ -525,7 +525,7 @@ GeglNode    * gegl_node_get_output_proxy (GeglNode      *node,
  * or NULL if no node is connected to the input_pad.
  */
 GeglNode    * gegl_node_get_producer     (GeglNode      *node,
-                                          gchar         *input_pad_name,
+                                          const gchar   *input_pad_name,
                                           gchar        **output_pad_name);
 
 /**