[gimp] Bug 764619: Color paint dynamic parameter and square artifacts when one or two channel are disabled

[Michael Schumacher <schumaml src gnome org>]

commit 3d58a233427848f856fa054414b3c237c12fc056
Author: Massimo Valentini <mvalentini src gnome org>
Date:   Tue Apr 5 12:14:06 2016 +0200

    Bug 764619: Color paint dynamic parameter and square artifacts when one or two channel are disabled

 app/paint/gimppaintcore.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/app/paint/gimppaintcore.c b/app/paint/gimppaintcore.c
index 9586c6f..83ed3b9 100644
--- a/app/paint/gimppaintcore.c
+++ b/app/paint/gimppaintcore.c
@@ -966,7 +966,10 @@ gimp_paint_core_paste (GimpPaintCore            *core,
                                       paint_opacity);
 
           /* dest_buffer -> paint_buf -> dest_buffer */
-          src_buffer = dest_buffer;
+          if (core->comp_buffer)
+            src_buffer = gimp_drawable_get_buffer (drawable);
+          else
+            src_buffer = dest_buffer;
         }
 
       do_layer_blend (src_buffer,