counsel-yank-pop ignores some kill-ring entries

I've noticed that counsel-yank-pop seems to not display some entries from the kill-ring. I don't know the exact criteria, but it seems to ignore short entries that contain contain non-ASCII characters.

For example, the following kill-ring entries do not appear in the counsel-yank-pop completion list:

"•"
"×"
"©" 

The entries:

"• "
"× "
"© " 

are similarly ignored. However the entries:

"• abcd"
"× abcd"
"© abcd"

and

"•
×
©"

all appear in the list as expected.

Also, an unrelated question:- if I do an accidental yank-pop (via M-y), Emacs tells me that the "Previous command was not a yank". However, the behaviour of counsel-yank-pop is different, bringing up the completion list regardless of the previous command. Can I change this?

If it matters, I'm running swiper 0.9.0 and mac-port Emacs 25.2.1 on macOS 10.12.4, although I see the same result on GNU NS Emacs.

I just tested a bit further and it seems counsel-yank-pop ignores all kill-ring entries less than three characters long. Is this intentional?

[abo-abo]

Is this intentional?

Well, it is in the code; I don't remember why I put it there. Probably because it's faster to type out 1-2 chars than to call counsel-yank-pop.

[abo-abo]

However, the behaviour of counsel-yank-pop is different, bringing up the completion list regardless of the previous command. Can I change this?

There's no reason to change it. The default restriction is pretty arbitrary and inconvenient. And you can quit counsel-yank-pop with C-g.

[abo-abo]

I removed the restriction. I guess it's useful for copying weird Unicode chars and selecting them with C-n.