set channel mask to the proper value (#5843)

ImageMagick · Dec 3, 2022 · 64d2830 · 64d2830
1 parent e9885fb
commit 64d2830
Showing 1 changed file with 20 additions and 33 deletions.
diff --git a/MagickCore/channel.c b/MagickCore/channel.c
@@ -73,7 +73,7 @@
 %
 %  ChannelFxImage() applies a channel expression to the specified image.  The
 %  expression consists of one or more channels, either mnemonic or numeric (e.g.
-%  red, 1), separated by actions as follows:
+%  r, red, 0), separated by actions as follows:
 %
 %    <=>     exchange two channels (e.g. red<=>blue)
 %    =>      copy one channel to another channel (e.g. red=>green)
@@ -122,20 +122,17 @@ static MagickBooleanType ChannelImage(Image *destination_image,
     *destination_view;
 
   MagickBooleanType
-    status;
+    status = MagickTrue;
 
   size_t
-    height,
-    width;
+    height = MagickMin(source_image->rows,destination_image->rows),
+    width = MagickMin(source_image->columns,destination_image->columns);
 
   ssize_t
     y;
 
-  status=MagickTrue;
   source_view=AcquireVirtualCacheView(source_image,exception);
   destination_view=AcquireAuthenticCacheView(destination_image,exception);
-  height=MagickMin(source_image->rows,destination_image->rows);
-  width=MagickMin(source_image->columns,destination_image->columns);
 #if defined(MAGICKCORE_OPENMP_SUPPORT)
   #pragma omp parallel for schedule(static) shared(status) \
     magick_number_threads(source_image,source_image,height,1)
@@ -196,43 +193,42 @@ MagickExport Image *ChannelFxImage(const Image *image,const char *expression,
 #define ChannelFxImageTag  "ChannelFx/Image"
 
   ChannelFx
-    channel_op;
+    channel_op = ExtractChannelOp;
 
   ChannelType
-    channel_mask;
+    channel_mask = image->channel_mask;
 
   char
-    token[MagickPathExtent];
+    token[MagickPathExtent] = "";
 
   const char
-    *p;
+    *p = expression;
 
   const Image
-    *source_image;
+    *source_image = image;
 
   double
-    pixel;
+    pixel = 0.0;
 
   Image
-    *destination_image;
+    *destination_image = (Image *) NULL;
 
   MagickBooleanType
-    status;
+    status = MagickTrue;
 
   PixelChannel
-    source_channel,
-    destination_channel;
+    source_channel = 0,
+    destination_channel = RedPixelChannel;
 
   ssize_t
-    channels;
+    channels = 0;
 
   assert(image != (Image *) NULL);
   assert(image->signature == MagickCoreSignature);
   if (IsEventLogging() != MagickFalse)
     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
   assert(exception != (ExceptionInfo *) NULL);
   assert(exception->signature == MagickCoreSignature);
-  source_image=image;
   destination_image=CloneImage(source_image,0,0,MagickTrue,exception);
   if (destination_image == (Image *) NULL)
     return((Image *) NULL);
@@ -244,13 +240,8 @@ MagickExport Image *ChannelFxImage(const Image *image,const char *expression,
       destination_image=GetLastImageInList(destination_image);
       return((Image *) NULL);
     }
-  destination_channel=RedPixelChannel;
-  channel_mask=UndefinedChannel;
-  pixel=0.0;
-  p=(char *) expression;
   (void) GetNextToken(p,&p,MagickPathExtent,token);
-  channel_op=ExtractChannelOp;
-  for (channels=0; *token != '\0'; )
+  while (*token != '\0')
   {
     ssize_t
       i;
@@ -267,10 +258,9 @@ MagickExport Image *ChannelFxImage(const Image *image,const char *expression,
       }
       case '|':
       {
+        source_image=GetFirstImageInList(source_image);
         if (GetNextImageInList(source_image) != (Image *) NULL)
           source_image=GetNextImageInList(source_image);
-        else
-          source_image=GetFirstImageInList(source_image);
         (void) GetNextToken(p,&p,MagickPathExtent,token);
         break;
       }
@@ -303,7 +293,7 @@ MagickExport Image *ChannelFxImage(const Image *image,const char *expression,
         (void) GetNextToken(p,&p,MagickPathExtent,token);
         channels=0;
         destination_channel=RedPixelChannel;
-        channel_mask=UndefinedChannel;
+        channel_mask=destination_image->channel_mask;
         break;
       }
       default:
@@ -357,10 +347,6 @@ MagickExport Image *ChannelFxImage(const Image *image,const char *expression,
               }
           }
         destination_channel=(PixelChannel) i;
-        if (i >= (ssize_t) GetPixelChannels(destination_image))
-          (void) SetPixelMetaChannels(destination_image,(size_t) (
-            destination_channel-GetPixelChannels(destination_image)+1),
-            exception);
         if (image->colorspace != UndefinedColorspace)
           switch (destination_channel)
           {
@@ -402,7 +388,8 @@ MagickExport Image *ChannelFxImage(const Image *image,const char *expression,
               break;
             }
           }
-        channel_mask=(ChannelType) (channel_mask | ParseChannelOption(token));
+        channel_mask=(ChannelType) (channel_mask |
+          (1UL << ParseChannelOption(token)));
         if (((channels >= 1)  || (destination_channel >= 1)) &&
             (IsGrayColorspace(destination_image->colorspace) != MagickFalse))
           (void) SetImageColorspace(destination_image,sRGBColorspace,exception);