From 3ca9ec1fec132c7e3c037a6fea16d8fdb9d3f29a Mon Sep 17 00:00:00 2001
From: anthony <anthony@git.imagemagick.org>
Date: Tue, 8 Jun 2010 07:16:04 +0000
Subject: [PATCH] Swap Multi-Kernel Composition order - and fix a 'image leak'

---
 magick/morphology.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/magick/morphology.c b/magick/morphology.c
index cdd8627ab..2304fd8af 100644
--- a/magick/morphology.c
+++ b/magick/morphology.c
@@ -2001,8 +2001,8 @@ MagickExport KernelInfo *AcquireKernelBuiltIn(const KernelInfoType type,
     case UnityKernel:
     default:
       {
-        /* Unity or No-Op Kernel - 3x3 with 1 in center */
-        kernel=ParseKernelArray("3:0,0,0,0,1,0,0,0,0");
+        /* Unity or No-Op Kernel - Basically just a single pixel on its own */
+        kernel=ParseKernelArray("1:1");
         if (kernel == (KernelInfo *) NULL)
           return(kernel);
         kernel->type = ( type == UnityKernel ) ? UnityKernel : UndefinedKernel;
@@ -2439,7 +2439,7 @@ static size_t MorphologyPrimitive(const Image *image, Image
     case HitAndMissMorphology:
     case ThinningMorphology:
     case ThickenMorphology:
-      /* kernel is user as is, without reflection */
+      /* kernel is used as is, without reflection */
       break;
     default:
       assert("Not a Primitive Morphology Method" != (char *) NULL);
@@ -3017,15 +3017,12 @@ MagickExport Image *MorphologyApply(const Image *image, const ChannelType
       stage_limit = 2;
       break;
     case HitAndMissMorphology:
-      kernel_limit = 1;          /* no method or kernel iteration */
       rslt_compose = LightenCompositeOp;  /* Union of multi-kernel results */
-      break;
+      /* FALL THUR */
     case ThinningMorphology:
     case ThickenMorphology:
-      method_limit = kernel_limit;  /* iterate method with each kernel */
+      method_limit = kernel_limit;  /* iterate the whole method */
       kernel_limit = 1;             /* do not do kernel iteration  */
-    case DistanceMorphology:
-      rslt_compose = NoCompositeOp; /* Re-iterate with multiple kernels */
       break;
     default:
       break;
@@ -3286,13 +3283,19 @@ MagickExport Image *MorphologyApply(const Image *image, const ChannelType
           ** below ensures the methematical compose method is applied in a
           ** purely mathematical way, and only to the selected channels.
           ** Turn off SVG composition 'alpha blending'.
+          **
+          ** The compose image order is specifically so that the new image can
+          ** be subtarcted 'Minus' from the collected result, to allow you to
+          ** convert a HitAndMiss methd into a Thinning method.
           */
           if ( verbose == MagickTrue )
             fprintf(stderr, " (compose \"%s\")",
                  MagickOptionToMnemonic(MagickComposeOptions, rslt_compose) );
-          (void) CompositeImageChannel(rslt_image,
+          (void) CompositeImageChannel(curr_image,
                (ChannelType) (channel & ~SyncChannels), rslt_compose,
-               curr_image, 0, 0);
+               rslt_image, 0, 0);
+          rslt_image = DestroyImage(rslt_image);
+          rslt_image = curr_image;
           curr_image = (Image *) image;  /* continue with original image */
         }
       if ( verbose == MagickTrue )
-- 
2.40.0