[gimp] app: fix handling of fully desaturated colors in lch chroma mode

[N/A <ell src gnome org>]

commit 1a2ef4149246df0d38b062c67b254b9b7a69d8d5
Author: Ell <ell_se yahoo com>
Date:   Fri Feb 3 13:55:30 2017 -0500

    app: fix handling of fully desaturated colors in lch chroma mode

 .../layer-modes/gimpoperationlayermode.c           |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/app/operations/layer-modes/gimpoperationlayermode.c 
b/app/operations/layer-modes/gimpoperationlayermode.c
index 66ac31b..263b58a 100644
--- a/app/operations/layer-modes/gimpoperationlayermode.c
+++ b/app/operations/layer-modes/gimpoperationlayermode.c
@@ -1600,6 +1600,12 @@ blendfun_lch_chroma (const float *dest,
               out[1] = A;
               out[2] = B;
             }
+          else
+            {
+              out[0] = dest[0];
+              out[1] = dest[1];
+              out[2] = dest[2];
+            }
         }
 
       out[ALPHA] = src[ALPHA];