Problem: when processing cycle such as
:for pat in [' \ze*', ' \zs*']
: try
: let l = matchlist('x x', pat)
: $put ='E888 NOT detected for ' . pat
: catch
: $put ='E888 detected for ' . pat
: endtry
:endfor
`:let l = …` throwing an error causes this error to be caught after
color_cmdline attempts to get callback for highlighting next line (the one with
`$put = 'E888 NOT…`). Saving/restoring state prevents this from happening.
This also attempted to fix problem with cancelling input() on error by avoiding
standard error printing facilities (assumed thrown error message is the
problem), but with no luck so far.