while looking at JBIDE-16904 I found that

A) all values are stored into content assist history when focus lost - incl. invalid and non valid values

B) the field does not update its list unless window recreated

C) the list keeps growing - seem to be no limit. I stopped after reaching 20 values of garbage

I would expect only values that the validator approves to be saved and could even go so far to only store the one that actually gets used on finish.

All my intermediate typing should not be considered okey for use IMO