'main': Fix issue #652.

highlighters/main/main-highlighter.zsh

@@ -548,7 +548,7 @@ _zsh_highlight_main_highlighter_highlight_list()
 
     if [[ $this_word == *':start:'* ]] && ! (( in_redirection )); then
       # Expand aliases.
-      _zsh_highlight_main__type "$arg"
+      _zsh_highlight_main__type "$arg" "$(( ! ${+seen_alias[$arg]} ))"
       local res="$REPLY"
       if [[ $res == "alias" ]] && [[ $last_alias != $arg ]]; then
         # Avoid looping forever on alias a=b b=c c=b, but allow alias foo='foo bar'