Thanks Ihor for the detailed explanation,
I updated the patch as you suggested.

On Sun, Feb 6, 2022 at 12:53 PM Ihor Radchenko <yantar92@gmail.com> wrote:

> Samim Pezeshki <p.samim@gmail.com> writes:
>
> > This commit prevents having extra spaces when the TODO format string is
> an
> > empty string ("").  It was not working properly, with this patch now it
> > works correctly.
>
> Thanks for the patch!
>
> >                 (concat
> >                  (substring x 0 (match-end 1))
> > ...
> > +       (unless (string= org-agenda-todo-keyword-format "")
> > +         (format org-agenda-todo-keyword-format
> > +                             (match-string 2 x))
> > +         ;; Remove `display' property as the icon could leak
> > +         ;; on the white space.
> > +         (org-add-props " " (org-plist-delete (text-properties-at 0 x)
> > +                                              'display)))
> >                     (substring x (match-end 3)))))))
> >        x)))
>
> Your patch will unconditionally hide todo keywords in agenda even when
> org-agenda-todo-keyword-format is not empty. This will happen because
> (unless ...) form will only return the last " ", but never the keyword.
>
> You should better wrap the (org-add-props ...) with another unless
> condition.
>
> Best,
> Ihor
>