fix(#3124): fix icon padding for "right_align" placements, notably for dotfiles

[rossw01]

fixes #3124

Bug is caused in builder.lua:

for _, d in ipairs(self.decorators) do
  add_to_end(rights, d:icons_right_align(not d:is(UserDecorator) and node or api_node))
end

In the case of tracked dotfiles, d:icons_right_align(not d:is(UserDecorator) and node or api_node) returns {} from the HiddenDecorator, but inside add_to_end(t1, t2) we only check if not t2. Not sure if this was intentional, I didn't notice any unexpected behaviour while testing but there may be edge cases I hadn't thought of.

[alex-courtis]

Not sure if this was intentional, I didn't notice any unexpected behaviour while testing but there may be edge cases I hadn't thought of.

That was not intentional; it was a bad copy-paste when creating the decorator classes. The same issue occurs for modified and this fix resolves it as well.

From the comment it looks like the :icons method originally tested self.explorer.opts.renderer.icons.show.git and similar, however that test was moved to the constructor. There's no need to change that as this fix covers it and will assist people with user decorators.

[alex-courtis]

Many thanks for your contribution!