DirChanged should fire whenever the result of getcwd() changes

[justinmk]

:help DirChanged says:

After the current-directory was changed.

But DirChanged only fires on an explicit call to e.g. :lcd. It should also fire when user focuses a window or tab which causes CWD to change. Example:

$ strace nvim -u NONE +'split|lcd ..|wincmd w' +qa 2>&1|grep chdir
chdir("/home/vagrant/neovim")           = 0
chdir("/home/vagrant")                  = 0
chdir("/home/vagrant/neovim")           = 0
chdir("..")                             = 0
chdir("/home/vagrant/neovim")           = 0  # DirChanged should fire here. 

see neovim/neovim-ruby#22 (comment)

cc @mhinz

[alexgenco]

I feel like the scope argument might make less sense in the case where it's not triggered by an explicit cd, lcd, or tcd. I suppose in your example it would be win, but I could imagine cases where it's not as clear cut, like switching to a split whose pwd was determined by a global directory change.

[justinmk]

Perhaps it's reasonable that "scope" is simply "the current effective scope" in those cases.

[justinmk]

like switching to a split whose pwd was determined by a global directory change.

In that case the scope would be "global", because that is the effective scope. Whether anyone will ever find this useful, I'm not sure. But the internal logic is such that exposing the conclusion is straightforward, so that's what we do.

This is implemented in #6262.