bug#70989: 29.3; Calling isearch-forward when using Unifont throws error "Invalid font name"

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Po Lu <luangruo@yahoo.com>
>> Cc: me@rodrigomorales.site,  70989@debbugs.gnu.org
>> Date: Sun, 19 May 2024 21:00:30 +0800
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> > Thanks, but why not replace all of those with a SPC?  It's simpler, I
>> > think.
>> 
>> No reason in particular, I simply thought it would be more elegant to
>> replace the other special characters with a different placeholder.
>
> I'd prefer to replace all the characters we cannot use there with a
> SPC, for consistency.
>
> Otherwise, I'm okay with the patch; please feel free to install.

Now done.  Rodrigo, please test and ack, and thanks.