git-annex/Git/CurrentRepo.hs
Joey Hess e50ed4ba48
work around git bug
Work around git bug that runs smudge/clean filters at the top of the
repository while passing them a relative GIT_WORK_TREE that may point
outside of the repository, by using GIT_PREFIX to get back to the
subdirectory where a relative GIT_WORK_TREE is valid.

git devs have been informed of the bug and may fix it, which could conveivably
break this fix, but as it is, this works back to git 1.7.6.

This commit was sponsored by Jochen Bartl on Patreon.
2018-07-17 14:27:39 -04:00

73 lines
2.1 KiB
Haskell

{- The current git repository.
-
- Copyright 2012 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Git.CurrentRepo where
import Common
import Git.Types
import Git.Construct
import qualified Git.Config
import Utility.Env
import Utility.Env.Set
{- Gets the current git repository.
-
- Honors GIT_DIR and GIT_WORK_TREE.
- Both environment variables are unset, to avoid confusing other git
- commands that also look at them. Instead, the Git module passes
- --work-tree and --git-dir to git commands it runs.
-
- When GIT_WORK_TREE or core.worktree are set, changes the working
- directory if necessary to ensure it is within the repository's work
- tree. While not needed for git commands, this is useful for anything
- else that looks for files in the worktree.
-
- Also works around a git bug when running some hooks. It
- runs the hooks in the top of the repository, but if GIT_WORK_TREE
- was relative, it then points to the wrong directory. In this situation
- GIT_PREFIX contains the directory that GIT_WORK_TREE (and GIT_DIR)
- are relative to.
-}
get :: IO Repo
get = do
prefix <- getpathenv "GIT_PREFIX"
gd <- pathenv "GIT_DIR" prefix
r <- configure gd =<< fromCwd
wt <- maybe (worktree $ location r) Just
<$> pathenv "GIT_WORK_TREE" prefix
case wt of
Nothing -> return r
Just d -> do
curr <- getCurrentDirectory
unless (d `dirContains` curr) $
setCurrentDirectory d
return $ addworktree wt r
where
getpathenv s = do
v <- getEnv s
case v of
Just d -> do
unsetEnv s
return (Just d)
Nothing -> return Nothing
pathenv s Nothing = getpathenv s
pathenv s (Just prefix) = getpathenv s >>= \case
Nothing -> return Nothing
Just d -> Just <$> absPath (prefix </> d)
configure Nothing (Just r) = Git.Config.read r
configure (Just d) _ = do
absd <- absPath d
curr <- getCurrentDirectory
Git.Config.read $ newFrom $
Local { gitdir = absd, worktree = Just curr }
configure Nothing Nothing = giveup "Not in a git repository."
addworktree w r = changelocation r $
Local { gitdir = gitdir (location r), worktree = w }
changelocation r l = r { location = l }