[gimp/gimp-2-10] Issue #1668 - Smudge Tool - Wrong colors when painting on an image ...

[Ell <ell src gnome org>]

commit 797bd3459bee58ff08d4e5b4b7d85c1d8818f561
Author: Ell <ell_se yahoo com>
Date:   Sun Jun 17 13:10:11 2018 -0400

    Issue #1668 - Smudge Tool - Wrong colors when painting on an image ...
    
    ... with a color profile other than the gimp built-in.
    
    Remove the separate alpha-channel copy in
    gimp_image_color_profile_srgb_to_pixel().  We no longer need it,
    since GimpColorTransform already takes care of that itself.
    
    We used babl_process() to copy the alpha, which would also
    transform the input color from R'G'B' to the output color space.
    When the same buffer was used for both input and output, this call
    would overwrite the input to the subsequent
    gimp_color_transform_process_pixels() call; when the output color
    space was different than R'G'B', this meant we'd pass the input to
    gimp_color_transform_process_pixels() in the wrong color space,
    producing wrong results.  This was the case when converting the
    foreground color for use with the smudge tool.
    
    (cherry picked from commit e58e2ec5dc0ac6ed27332a29c6059452fcff7d13)

 app/core/gimpimage-color-profile.c | 3 ---
 1 file changed, 3 deletions(-)
---
diff --git a/app/core/gimpimage-color-profile.c b/app/core/gimpimage-color-profile.c
index 27dc6b0b3e..0fc71a2d67 100644
--- a/app/core/gimpimage-color-profile.c
+++ b/app/core/gimpimage-color-profile.c
@@ -604,9 +604,6 @@ gimp_image_color_profile_srgb_to_pixel (GimpImage     *image,
 
   if (transform)
     {
-      /* for the alpha channel */
-      gimp_rgba_get_pixel (color, pixel_format, pixel);
-
       gimp_color_transform_process_pixels (transform,
                                            babl_format ("R'G'B'A double"),
                                            color,