In vim, background color changes on scrolling

Question

Occasionally I get a weird error with the background color in vim when scrolling up in a long file. The background over the text is correct, but everywhere there is no printable character the background turns black.

After a bit of hunting and experimenting, I have found that :redraw! fixes the problem, but I would like to know why this occurs and if there is anything I can do to permanently fix the issue.

Although I have gotten this error to occur with other color schemes, for what it is worth I am using the lucius color scheme with vim 7.3 editing a bunch of python files.

Answer 1

As explained here and here, you can fix this by turning off Background Color Erase. Change in your .vimrc:

if &term =~ '256color'
    " Disable Background Color Erase (BCE) so that color schemes
    " work properly when Vim is used inside tmux and GNU screen.
    set t_ut=
endif

You can also type Ctrl+L to reset the screen.

Answer 2

This may be a plugin or configuration related, perhaps try

vim -u NONE

to load vim without the vimrc and without plugins and see if the problem persists.

As far as configuration, I think you should probably look at lazyredraw and ttyfast.

You can read the documetation by typing (:help lazyredraw) and find out if you've unknowingly set it (:set lazyredraw?) and probably unset it (:set nolazyredraw).

And it may help if you set ttyfast (:help ttyfast).