vis: improve new line handling at end of file

<Enter> at the end of the file now inserts two newlines, unless there is
already one in place. This ensures that in 'normal' operation the file
is always new line terminated (as mandated by POSIX). It also means that
there is no problem displaying the right amount of ~ symbols at the end
of the file.

Unlike in vim the cell beyond the end of the file remains adressable
even in normal mode. This means something like the following (starting
from an empty file) might be a little confusing:

 o<Escape><Left>dd

Because the starting position is beyond the last newline of the file,
nothing will be deleted.

For now we prefer to avoid the additional complexity, and difference
in behavior between normal and insert mode, needed to fix this slight
inconsistency.

Fix #294

0 files changed, 0 insertions, 0 deletions