From: Shroom Moo <egg_mushroomcow@foxmail.com>
Date: Fri, 22 May 2026 15:09:26 GMT
Subject: Re: [PATCH v2 07/11] git-gui: try harder to find worktree from gitdir
Message-ID: <tencent_9FA5CF10A1D7CAC770366E84AD5CA9A2D107@qq.com>
In-Reply-To: <780a52d9-7119-4870-990a-16280005503d@gmail.com>

On 5/22/26 1:45 AM, Mark Levedahl wrote:
> >
> > Additionally, [file exists {gitdir}] checks for the gitdir file in 
> > the current working directory. Since the function has not yet 
> > switched to $_gitdir when this check runs, it is almost impossible 
> > to find the file. Consequently, this logic never triggers, preventing 
> > linked worktrees from being recognized. 
> >
> > Maybe the identification of linked worktree should not directly look 
> > for the gitdir file, but should check whether there is a.git file and 
> > its content points to... /.git/worktrees/... ? Anyways, using the 
> > literal {gitdir} to search in the current directory lead to risks. 
> >
> > Shroom
> >
> We cannot get to this code if not inside the gitdir, and if the user set GIT_DIR and/or
> GIT_WORK_TREE to do something clever, that either worked or the code already threw an
> error. git, without GIT_WORK_TREE set, uses the current directory as the worktree, or the
> parent directory containing .git. So, we must be inside the gitdir if this code path gets hit.
> 
> Mark

The relative path issue with {gitdir} is indeed difficult to trigger 
in practice. To trigger this problem, the following conditions must 
be met simultaneously: 
- git rev-parse --absolute-git-dir succeeds (the repository is valid). 
- git rev-parse --show-toplevel fails (the working tree is 
undetectable).
- The current directory is not $_gitdir.
- A gitdir file exists under $_gitdir (i.e., the gitdir of a linked 
worktree). 

Unluckily, this occurs in:

```MINGW64 Shell
# Firstly, enter a test folder
mkdir test-main
cd test-main

git init

echo main > file.txt
git add file.txt
git commit -m "initial"

# In feature branch
git branch feature

# Add worktree
git worktree add ../test-feature feature

cd ../
cd test-feature
cat .git

cd ../

mkdir outside
cd outside

export GIT_DIR="/(PREVIOUSPATH)/test-main/.git/worktrees/feature"
unset GIT_WORK_TREE
git gui blame HEAD file.txt --trace
```

```Wish
puts $_gitworktree
```

The current directory is "outside", not the expected linked worktree. 
[file exists {gitdir}] in find_worktree_from_gitdir searched in the 
current directory but failed, resulting in the inability to identify 
linked worktree. The blame mode can still work without worktree. 

Shroom