From d197cbbbde474ea2cbdd56d0defa45f100e44cd0 Mon Sep 17 00:00:00 2001
From: cristy <urban-warrior@git.imagemagick.org>
Date: Fri, 13 Jan 2012 02:14:12 +0000
Subject: [PATCH]

---
 MagickCore/composite.c | 23 ++++++++++++++---------
 MagickWand/mogrify.c   |  9 ++++++---
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/MagickCore/composite.c b/MagickCore/composite.c
index 34f2d3b32..dfa66d78e 100644
--- a/MagickCore/composite.c
+++ b/MagickCore/composite.c
@@ -531,12 +531,12 @@ MagickExport MagickBooleanType CompositeImage(Image *image,
   MagickStatusType
     flags;
 
-  ssize_t
-    y;
-
   size_t
     channels;
 
+  ssize_t
+    y;
+
   /*
      Composition based on the SVG specification:
 
@@ -584,7 +584,6 @@ MagickExport MagickBooleanType CompositeImage(Image *image,
          performed as 'pure' mathematical operations, rather than as image
          operations.
   */
-
   assert(image != (Image *) NULL);
   assert(image->signature == MagickSignature);
   if (image->debug != MagickFalse)
@@ -1581,6 +1580,7 @@ MagickExport MagickBooleanType CompositeImage(Image *image,
             break;
         }
         gamma=1.0/(fabs(alpha) <= MagickEpsilon ? 1.0 : alpha);
+        pixel=Dc;
         switch (compose)
         {
           case AlphaCompositeOp:
@@ -1694,30 +1694,35 @@ MagickExport MagickBooleanType CompositeImage(Image *image,
           case CopyAlphaCompositeOp:
           case IntensityCompositeOp:
           {
-            pixel=Dc;
+            if (channel == AlphaPixelChannel)
+              pixel=(MagickRealType) GetPixelAlpha(composite_image,p);
             break;
           }
           case CopyBlackCompositeOp:
           {
-            pixel=(MagickRealType) GetPixelBlack(composite_image,p);
+            if (channel == BlackPixelChannel)
+              pixel=(MagickRealType) GetPixelBlack(composite_image,p);
             break;
           }
           case CopyBlueCompositeOp:
           case CopyYellowCompositeOp:
           {
-            pixel=(MagickRealType) GetPixelBlue(composite_image,p);
+            if (channel == BluePixelChannel)
+              pixel=(MagickRealType) GetPixelBlue(composite_image,p);
             break;
           }
           case CopyGreenCompositeOp:
           case CopyMagentaCompositeOp:
           {
-            pixel=(MagickRealType) GetPixelGreen(composite_image,p);
+            if (channel == GreenPixelChannel)
+              pixel=(MagickRealType) GetPixelGreen(composite_image,p);
             break;
           }
           case CopyRedCompositeOp:
           case CopyCyanCompositeOp:
           {
-            pixel=(MagickRealType) GetPixelRed(composite_image,p);
+            if (channel == RedPixelChannel)
+              pixel=(MagickRealType) GetPixelRed(composite_image,p);
             break;
           }
           case DarkenCompositeOp:
diff --git a/MagickWand/mogrify.c b/MagickWand/mogrify.c
index d7202e277..704e22603 100644
--- a/MagickWand/mogrify.c
+++ b/MagickWand/mogrify.c
@@ -7479,8 +7479,8 @@ WandExport MagickBooleanType MogrifyImageList(ImageInfo *image_info,
                 else
                   {
                     /*
-                      Set a blending mask for the composition.
-                      Posible error, what if image->mask already set.
+                      Set a blending mask for the composition.  Possible
+                      problem, what if image->mask already set.
                     */
                     image->mask=mask_image;
                     (void) NegateImage(image->mask,MagickFalse,exception);
@@ -7489,7 +7489,10 @@ WandExport MagickBooleanType MogrifyImageList(ImageInfo *image_info,
             (void) CompositeImage(image,image->compose,composite_image,
               geometry.x,geometry.y,exception);
             if (mask_image != (Image *) NULL)
-              mask_image=image->mask=DestroyImage(image->mask);
+              {
+                image->mask=DestroyImage(image->mask);
+                mask_image=(Image *) NULL;
+              }
             composite_image=DestroyImage(composite_image);
             *images=DestroyImageList(*images);
             *images=image;
-- 
2.40.0