fix(loader): respect empty colorscheme (#713)

[lbonn]

This gives the option to not override default colorscheme during plugin installation by using the configuration:

{
    install = {
        colorscheme = {},
    },
}

If the user specifies a scheme or keeps the default, we will fall back to 'habamax' as before.

Note: the simple fix is to just remove the line and expect users to explicitly use ['theme1', 'habamax'] if needed but I tried to stay closer to the current semantics.

[folke]

Just add "default" as the colorscheme you want to use?

[lbonn]

@folke

Just add "default" as the colorscheme you want to use?

I have tried but reloading the "default" colorscheme resets background=dark, so it will render badly on a setup with background=light.

[tvsfx]

I just ran into this; it would be nice if default retained the background setting when installing plugins.

[folke]

I agree. This should be fixed in Neovim. Lazy doesn't do anything special that resets the background or anything like that.

[folke]

Now that I think about it, what probably happens is that lazy loads the colorscheme before Neovim has determined the correct background. There's multiple issues related to this in the Neovim repo. Not really much I can do.

[lbonn]

@folke there is nothing special with timing afaik, it also happens if :colorscheme default is invoked later which, I agree, is not great.

Actually, it's been fixed in neovim's tip where removed the set bg& in default.vim at the same time as they introduced a new default scheme (old default is vim.vim): neovim/neovim@574519d#diff-bddb1a5052ac511ac44f15f009566304ed3d9d7746609f9a2902235478f2b4cd

In the meantime, I think it is useful to have a way to configure lazyvim to not touch the colorscheme at all. But it's true it's only happening during the install phase and it's ultimately your call.

[folke]

When you now configure it to use "default", then it should work as expected. I simply don't load any colorscheme when "default"