On Wed, Sep 20, 2017 at 12:16 PM Eli Zaretskii <eliz@gnu.org> wrote:

> I don't understand the exact meaning of those numbers "0 2", but looks like that limits the number of
> characters to be displayed after "test:"?

No, it means that the face covers 2 characters starting with the first
one.

Thanks.

I don't think I understand all the complexity you've gone through,
because this works for me in the current emacs-26 branch:

(insert (format (propertize "%d" 'face 'font-lock-warning-face) 10))

That works, and so I had to come up with this recipe. Can you see the problem too if you follow this recipe? Did you also see the screenshots I took based on this recipe in emacs -Q?

How is this different from what you do?

It probably has something to do with a function call (test-incr) instead of a static value like 10?