Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> More or less. If you don't add these chars, mbcliplen doesn't think
> there's character there, so it ends up not adding the ellipsis. (I
> don't remember why it has to be two chars rather than just one.)
I think the idea is to be sure that there's a full multibyte character
after the truncation point; if the truncation point is within a multibyte
character, then you might have only a partial multibyte character after
that, which could cause problems. Doing it this way, mbcliplen will
never look at the last possibly-truncated character.
regards, tom lane