bug#67764: 30.0.50; Opening image in eww no longer works

[john muhl]

Visuwesh <visuweshm@gmail.com> writes:

> [Monday December 11, 2023] john muhl via "Bug reports for GNU Emacs,
> the Swiss army knife of text editors" wrote:
>
>> In Emacs 29.1 the image opens as expected:
>>
>>   emacs -Q
>>   M-: (eww "https://www.gnu.org/software/emacs/images/emacs.png";)
>>
>> On master it fails with "Wrong type argument: stringp, nil".
>> Bisect says 4254544 is the first bad commit.
>
> Recent changes in shr-put-image didn't account for the possible nil
> value for ALT.  Attached patch fixes the issue on my end.

Thanks. That fixes it here too.