Lawrence Mitchell <wence@gmx.li> writes:

> Bastien wrote:
>
> [...]
>
>> Right.  I have come up with another solution, not relying on font-lock,
>> but this one doesn't allow the double-quote character in comments.
>
>> Please improve it if you can.  If no objection/suggestion until next
>> week, I'll apply this one.
>
> I think the right way to fix this is to allow ielm to read the
> form as it currently does (using read-from-string) and then
> discard following input if it contains either merely whitespace
> (as is currently the case) or a comment.

Of course, you're right.  
I haven't seen your first patch, sorry. 

I propose this slightly modified patch below: it uses 

  "\\`[ \t\n]*\\(?:;.*\\)*\\'"
             ^
             ^

in `ielm-is-whitespace-or-comment' so that a sexp like

  (message "test");; comment
                  ^ <= no whitespace

doesn't return an error.

I will apply this with the ChangeLog you provided if you agree.  

Thanks,