input-pending-p after make-frame-visible

[Aaron Jensen]

Hi all,

Unfortunately, I don't have a repro for this, but I'm putting it out
there in case anyone has any insight into it.

There is a package that makes it so that your minibuffer is rendered
into a child-frame called mini-frame:
https://github.com/muffinmad/emacs-mini-frame/

I've noticed that at some point, Emacs gets into a state where after
make-frame-visible is called with the child frame, input-pending-p
starts returning t, rather than nil:

    (message "pending: %S" (input-pending-p))
    (make-frame-visible mini-frame-frame)
    (message "pending: %S" (input-pending-p))

Prints:

nil
t

Source: 
https://github.com/muffinmad/emacs-mini-frame/blob/57a049b9e1ea4a9b65e82fc10c8c7e70a042f636/mini-frame.el#L313

This ordinarily wouldn't matter, but I use it with a package that uses
while-no-input and this unexpected input causes issues with that
package (https://github.com/minad/vertico/issues/115).

What could possibly cause an input to become pending when the frame is
made visible?

Thanks,

Aaron