[gimp] Bug 577301 – Dithering with transparency is broken for "positioned" method

[Sven Neumann <neo src gnome org>]

commit cbfe411ea15a4dcc6d919123022ed37bcd951b60
Author: Sven Neumann <sven gimp org>
Date:   Thu May 21 19:00:37 2009 +0200

    Bug 577301 â?? Dithering with transparency is broken for "positioned" method
    
    Applied patch from Rob Antonishen fixing the reported transparency
    dithering issue.
---
 app/core/gimpimage-convert.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/core/gimpimage-convert.c b/app/core/gimpimage-convert.c
index 3ded0c9..ccbec21 100644
--- a/app/core/gimpimage-convert.c
+++ b/app/core/gimpimage-convert.c
@@ -2964,7 +2964,7 @@ median_cut_pass2_fixed_dither_gray (QuantizeObj *quantobj,
 
                   if (alpha_dither)
                     {
-                      if ((src[ALPHA_G] << 6) < (255 * dmval))
+                      if (src[ALPHA_G] < dmval)
                         transparent = TRUE;
                     }
                   else
@@ -3198,7 +3198,7 @@ median_cut_pass2_fixed_dither_rgb (QuantizeObj *quantobj,
 
                   if (alpha_dither)
                     {
-                      if ((src[alpha_pix] << 6) < (255*dmval))
+                      if (src[alpha_pix] < dmval)
                         transparent = TRUE;
                     }
                   else