[gimp] app: show the dither dialog when converting between linear and gamma

[Michael Natterer <mitch src gnome org>]

commit 5506e691b666b53c74f2ff26d434e41875677d39
Author: Michael Natterer <mitch gimp org>
Date:   Sun Jun 23 17:15:30 2013 +0200

    app: show the dither dialog when converting between linear and gamma
    
    within one bit depth.

 app/actions/image-commands.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/app/actions/image-commands.c b/app/actions/image-commands.c
index 3aead0a..daa32cc 100644
--- a/app/actions/image-commands.c
+++ b/app/actions/image-commands.c
@@ -26,6 +26,8 @@
 
 #include "config/gimpcoreconfig.h"
 
+#include "gegl/gimp-babl.h"
+
 #include "core/core-enums.h"
 #include "core/gimp.h"
 #include "core/gimpchannel.h"
@@ -246,7 +248,8 @@ image_convert_precision_cmd_callback (GtkAction *action,
   if (value == gimp_image_get_precision (image))
     return;
 
-  if (value < gimp_image_get_precision (image))
+  if ((value < gimp_image_get_precision (image)) ||
+      (gimp_babl_component_type (value) == gimp_image_get_component_type (image)))
     {
       GtkWidget *dialog;