tig does not show files inside subdir of worktree when $GIT_DIR is set

[g-raud]

Using tig 2.2 or 2.3.0 the CWD is ignored to qualify relative paths if GIT_DIR is set; all paths must be given relative to the GIT_WORK_TREE it seems. This is annoying, particularly with vcsh (that sets a GIT_DIR inside ~/.config with a GIT_WORK_TREE of ~/), and is not what git-log does. Example:

cd ~
vcsh init test
vcsh test add .config/tig/tigrc
vcsh test commit -m 'tigrc'
vcsh test tig -- .config/tig/tigrc # shows the commit
vcsh test log -- .config/tig/tigrc # does not show anything
cd .config/
vcsh test tig -- tig/tigrc # fails (No revisions match the given arguments.) 
vcsh test log -- tig/tigrc # shows the commit
vcsh test tig -- .config/tig/tigrc # shows the commit
vcsh test log -- .config/tig/tigrc # does not show anything

[jonas]

Worktree support is lacking to the extend of even being broken.

I do not personally use worktrees so any contributions in the area would be much appreciated.

[jonas]

When running tig as a git alias, git will chdir(GIT_WORK_TREE) and pass the subdirectory tig was invoked in as GIT_PREFIX. So the fix is to chdir(GIT_PREFIX).