RE: Why does show_help_echo call substitute_command_keys?

[Drew Adams]

> > Ok. So we don't expect callers to explicitly use substitute-command-keys
> on their help-echo properties?
> 
> Imagine if it were so.
> 
> You add a button to the tool bar, with a help-echo property containing
> tooltip text with command keys substituted at the time of addition.
> 
> The user rebinds the command to another key. Your button retains its
> (now inaccurate) tooltip text.

Which just means that your code isn't good enough.

If you hard-code a `help-echo' property to ANYTHING and some
later changes make that value no longer appropriate...