fix issue 177 (#200)

pkg/mark/attachment.go

@@ -42,16 +42,16 @@ func ResolveAttachments(
 		return nil, err
 	}
 
-	for _, attach := range attaches {
-		checksum, err := getChecksum(attach.Path)
+	for i, _ := range attaches {
+		checksum, err := getChecksum(attaches[i].Path)
 		if err != nil {
 			return nil, karma.Format(
 				err,
-				"unable to get checksum for attachment: %q", attach.Name,
+				"unable to get checksum for attachment: %q", attaches[i].Name,
 			)
 		}
 
-		attach.Checksum = checksum
+		attaches[i].Checksum = checksum
 	}
 
 	remotes, err := api.GetAttachments(page.ID)
@@ -147,6 +147,10 @@ func ResolveAttachments(
 		updating[i] = attach
 	}
 
+	for i, _ := range existing {
+		log.Infof(nil, "keeping unmodified attachment: %q", attaches[i].Name)
+	}
+
 	attaches = []Attachment{}
 	attaches = append(attaches, existing...)
 	attaches = append(attaches, creating...)