[gimp] app: make darken only and lighten only work in linear

[Øyvind Kolås <ok src gnome org>]

commit b88d74da24b8ab18636669738afacffea5e90c90
Author: Øyvind Kolås <pippin gimp org>
Date:   Tue Jan 24 02:52:25 2017 +0100

    app: make darken only and lighten only work in linear
    
    Gamma doesn't change sort order of floats.

 app/core/gimp-layer-modes.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/app/core/gimp-layer-modes.c b/app/core/gimp-layer-modes.c
index 488e493..13b08b3 100644
--- a/app/core/gimp-layer-modes.c
+++ b/app/core/gimp-layer-modes.c
@@ -185,20 +185,24 @@ gimp_layer_mode_get_blend_space (GimpLayerMode  mode)
     case GIMP_LAYER_MODE_BEHIND:
       return GIMP_LAYER_COLOR_SPACE_RGB_PERCEPTUAL;
 
+    case GIMP_LAYER_MODE_DARKEN_ONLY:
+    case GIMP_LAYER_MODE_LIGHTEN_ONLY:
+      return GIMP_LAYER_COLOR_SPACE_RGB_LINEAR;
+
     case GIMP_LAYER_MODE_MULTIPLY_LEGACY:
     case GIMP_LAYER_MODE_SCREEN_LEGACY:
     case GIMP_LAYER_MODE_OVERLAY_LEGACY:
     case GIMP_LAYER_MODE_DIFFERENCE_LEGACY:
     case GIMP_LAYER_MODE_ADDITION_LEGACY:
     case GIMP_LAYER_MODE_SUBTRACT_LEGACY:
-    case GIMP_LAYER_MODE_DARKEN_ONLY_LEGACY:
-    case GIMP_LAYER_MODE_LIGHTEN_ONLY_LEGACY:
     case GIMP_LAYER_MODE_HSV_HUE_LEGACY:
     case GIMP_LAYER_MODE_HSV_SATURATION_LEGACY:
     case GIMP_LAYER_MODE_HSV_COLOR_LEGACY:
     case GIMP_LAYER_MODE_HSV_VALUE_LEGACY:
     case GIMP_LAYER_MODE_DIVIDE_LEGACY:
     case GIMP_LAYER_MODE_DODGE_LEGACY:
+    case GIMP_LAYER_MODE_DARKEN_ONLY_LEGACY:
+    case GIMP_LAYER_MODE_LIGHTEN_ONLY_LEGACY:
     case GIMP_LAYER_MODE_BURN_LEGACY:
     case GIMP_LAYER_MODE_HARDLIGHT_LEGACY:
     case GIMP_LAYER_MODE_SOFTLIGHT_LEGACY:
@@ -224,8 +228,6 @@ gimp_layer_mode_get_blend_space (GimpLayerMode  mode)
     case GIMP_LAYER_MODE_DIFFERENCE:
     case GIMP_LAYER_MODE_ADDITION:
     case GIMP_LAYER_MODE_SUBTRACT:
-    case GIMP_LAYER_MODE_DARKEN_ONLY:
-    case GIMP_LAYER_MODE_LIGHTEN_ONLY:
     case GIMP_LAYER_MODE_HSV_HUE:
     case GIMP_LAYER_MODE_HSV_SATURATION:
     case GIMP_LAYER_MODE_HSV_COLOR: