From 9bca83b6db0b3d6f5e307cc5c4103309a249ea98 Mon Sep 17 00:00:00 2001
From: Cristy <urban-warrior@imagemagick.org>
Date: Sat, 11 Feb 2017 20:16:04 -0500
Subject: [PATCH] ...

---
 ChangeLog          |  2 ++
 MagickCore/pixel.c | 21 ++++++++++-----------
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 79cf1fe94..97db83a0c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -9,6 +9,8 @@
     https://blog.awm.jp/2017/02/09/imagemagick-en/).
   * Return unbiased standard deviation for image statistics (reference
     https://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=31377).
+  * Don't set update trait on alpha channel (private e-mail concerning
+    -levels-colors option).
 
 2017-02-04  7.0.4-7 Cristy  <quetzlzacatenango@image...>
   * Release ImageMagick version 7.0.4-7, GIT revision 19513:5783e57:20170204.
diff --git a/MagickCore/pixel.c b/MagickCore/pixel.c
index 0a5f0c2ed..4d8c35bc8 100644
--- a/MagickCore/pixel.c
+++ b/MagickCore/pixel.c
@@ -4321,8 +4321,8 @@ static void LogPixelChannels(const Image *image)
   register ssize_t
     i;
 
-  (void) LogMagickEvent(PixelEvent,GetMagickModule(),"%s[%.20g]",
-    image->filename,(double) image->number_channels);
+  (void) LogMagickEvent(PixelEvent,GetMagickModule(),"%s[%08x]",
+    image->filename,image->channel_mask);
   for (i=0; i < (ssize_t) image->number_channels; i++)
   {
     char
@@ -4466,7 +4466,7 @@ MagickExport void InitializePixelChannelMap(Image *image)
   image->number_channels=(size_t) n;
   if (image->debug != MagickFalse)
     LogPixelChannels(image);
-  SetImageChannelMask(image,image->channel_mask);
+  SetPixelChannelMask(image,image->channel_mask);
 }
 
 /*
@@ -6292,15 +6292,14 @@ MagickExport ChannelType SetPixelChannelMask(Image *image,
             SetPixelChannelTraits(image,channel,CopyPixelTrait);
             continue;
           }
-        SetPixelChannelTraits(image,channel,UpdatePixelTrait);
-        continue;
-      }
-    if (image->alpha_trait != UndefinedPixelTrait)
-      {
-        SetPixelChannelTraits(image,channel,(const PixelTrait)
-          (UpdatePixelTrait | BlendPixelTrait));
-        continue;
       }
+    else
+      if (image->alpha_trait != UndefinedPixelTrait)
+        {
+          SetPixelChannelTraits(image,channel,(const PixelTrait)
+            (UpdatePixelTrait | BlendPixelTrait));
+          continue;
+        }
     SetPixelChannelTraits(image,channel,UpdatePixelTrait);
   }
   if (image->storage_class == PseudoClass)
-- 
2.40.0